Survival at stake

Published : Sep 06, 1997 00:00 IST

The tiger population has fallen sharply in the Nagarjunasagar Srisailam Tiger Reserve, the largest reserve of its kind in the country.

THE Nagarjunasagar Srisailam Tiger Reserve (NSTR), the largest tiger reserve in India, is in the Nallamalais in Andhra Pradesh. It is spread over five districts and encompasses more than 3,500 sq km. The reserve was home to about 100 tigers at the beginning of this decade. However, according to a census conducted in 1997, the tiger population has fallen steeply, to about 20.

The importance of tiger conservation lies in the fact that the presence of this predator is an indicator of the health of an ecosystem. A natural forest in which the tiger thrives offers benefits that cannot be quantified easily in terms of money. These include protection of the topsoil; retention of groundwater, which is released through the year; and preservation of biomass resources and the flora. Bamboo, fuelwood, timber and fodder and at least 20 types of other forest produce such as honey, gum and arabic directly or indirectly help thousands of people earn their living; the flora include several plants that are traditionally used in medicine.

As much as 800 million units of electricity consumed in Andhra Pradesh is generated using the waters of the Krishna, and the NSTR forms part of the catchment area of the river. The Nagarjunasagar and Srisailam hydro-electric projects are located within the reserve.

The balance of the forest ecosystem is maintained by the interaction between its components. The flora need herbivores for the propagation of seeds over wide areas, while herbivores cannot survive without the flora. At the same time, the herbivore population has to be kept in check to prevent over-exploitation of the flora. Carnivores perform this function. In the NSTR, the tiger is the major carnivore.

Thus, protecting the tiger essentially means protecting the ecosystem. A fall in the tiger population is a clear indication of a decline in the forest's overall health.

IN forests that are spread over inhospitable terrain and are predominantly of the dry deciduous type, as is the case with the Nallamalais, the most suitable way to assess the tiger population is the waterhole census. The logic of this system is that since the reserve has limited water sources, those that remain wet through the summer would definitely draw wildlife to them (the periodicity of such visits will, however, vary between species). Thus, perennial water sources - called cheruvus, chelimas and dotas - are of prime importance, and the census is conducted in summer by monitoring them for days together.

We were present in the NSTR area in three different periods during the annual tiger census in April-May 1995. Our objective was to get an idea of the population of tigers and their food base - chital, sambhar, wild boar, chausingha, barking deer, chinkara and so on. We used the 1989 and 1993 figures for reference with respect to the areas in which the predators were more likely to be traced. We visited as many of these locations as possible.

The 1997 Tiger Census provides a dismal picture. The situation in the Amrabad plateau, which is to the north of the Krishna and which supported the largest number of tigers in the area, is worse than in 1995. The forests across the Dindi river and those in Guntur district, across the Krishna, cover much smaller areas; they act as crucial buffers for the reserve, but cannot by themselves support viable populations of wildlife.

Year Number of Tigers1989 941993 541995 351997 25-30

The decline in the tiger population in the country's largest national park has taken place despite Project Tiger. Apart from this fact, the poor state of the vegetation and the diminishing number of large mammals, especially herbivores, also point to the alarming state of affairs in the area. Much of the flora of the Nallamalais are being destroyed even before they are recorded. That such natural wealth is handled so casually shows how misplaced our societal priorities are.

The degradation of the forest, combined with the semi-arid climate of the region, has adversely affected the sanctuary. The Krishna, which was fordable prior to the construction of the Nagarjunasagar and Srisailam dams, has now become a barrier which the animals cannot cross. A significant part of the sanctuary towards the north-east is fragmented by man-made water bodies into small, degraded habitats. These areas have to be protected to provide wildlife room to migrate when necessary, and also to act as a buffer against biotic pressures. But the buffer itself has been so over-exploited that biotic pressures are now degrading the core area.

The evolving demographic profile of the towns and villages surrounding the forests indicates the changes and pressures. The population, both resident and floating, has increased several fold. Most people, though classified as dependent on agriculture, are employed in farming only during the monsoon season. At other times they depend on the forest to make a living - by collecting and selling firewood or non-timber forest produce, and in some cases, smuggling out timber. Several saw-mills have come up close to the reserve.

The Nallamalais provide fodder for thousands of cattle. In the absence of a grazing policy, local people graze their cattle in the forest, after paying a fee, and often deprive wildlife access to these resources.

Sustainable use of available resources can help retain the economic and ecological value of the forest in terms of biomass availability, increased water retention capacity and fertility of the soil. Thanks to its resilience and adaptability, the tiger of the NSTR has hung on tenaciously; now it is up to humans to try and give it a future. The question now is whether an unviable population can have a future of any significance. Lakhs of rupees are now spent on preservation programmes for the tiger; how well they serve the cause of conservation must be studied closely.

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