Its habitat is shrinking and forests getting sparse, a forest survey based on satellite imagery showed. Of the 28 forest reserves, 11 are showing decline in forest cover. The reasons are: pressure by human habitation inside and on the periphery of the reserves, encroachment and illegal felling.

The report of shrinking tiger habitats comes at a time when the UPA Government is poised at legalising land rights to forest dwellers under the Tribal Rights Bill. Wildlifers have expressed grave concerns that the move will further exert pressure on the fragile ecology and undermine tiger conservation.

The Bill seeks to give legal rights to tribals residing in forest till 1980 and up to 2.5 ha where they are living right now. Government estimates suggest about two million people live inside forests, some in the core areas of national parks, and could become permanent residents of the forests.

A significant part of forest land is expected to be diverted for granting legal rights to tribals. Their dependence on forests and economic aspirations are worrying those concerned about keeping tiger habitats free from human interference.

Tiger reserves of Nameri, Manas, Indravati, Buxa and Dampa have showed a significant loss of forest cover while Bandipur-Nagarhole, Dudhwa-Katarniaghat, Kanha, Pakhui, Palamu and Sunderbans are also showing declining trends in forest cover. These reserves are under threat from human habitations within and outside the reserve, encroachment and cattle grazing.

The Forest Survey of India report on forest cover in tiger reserves of India for the first time showed that the loss of forest in the 10 kilometres radial distance from the periphery of the reserve is quite significant. Outer forests health is crucial as it buffers the reserve from external pressures and enhances the prey base for the wild cats.

The report noted that forest cover decreased in 11 tiger reserves during the five-year period between 1997 and 2002 ranging from seven to 45 sq km in the worst affected reserves and less than four sq km in other reserves.

Buxa tiger Reserve has shown more decrease in forest cover during 2000-2002 mainly due to flooding of the river flowing through the reserve. Decrease in forest cover in Nameri, Manas, and Indravati Tiger Reserves could be due to illicit felling and encroachment, the report noted. Shifting cultivation is considered the main reason for the decrease in forest cover in Dampa and Pakhui Tiger Reserves. The meandering course of Mohana seems to be the major cause of decrease in forest cover in Dudhwa-Katarniaghat Tiger Reserve, while the ebb erosion in Mayadweep island is likely reason for the decrease in Sunderbans Tiger Reserve. Felling and encroachment could be the main reason for decrease in Kanha and Palamu Tiger Reserves, while a Nagpur rehabilitation centre inside Bandipur Tiger Reserve.

Those ducking the trend of shrinking forest cover are Bandhavgarh, Corbett, Nagarjunasagar-Srisailam, Namdapha and Valmiki Tiger Reserves where the forest area has increased by up to 7 sq km.

The outer forest cover loss is more than the loss within tiger reserves. Those reserves showing decrease in forest cover also shows significant loss in outer forests as observed in Nameri, Dampa, Buxa and Palamu.

While poaching is an immediate threat for tiger conservation, habitat loss is of far serious consequence. To regenerate and improve destroyed habitat is difficult if not practically irreversible. The cats are hemmed in within a shrinking space of its home.