One is happy that the editorial (Jan.23) acknowledges the fact that the science of conserving tigers is mostly focussed on saving “source populations” of the cat. However, a major challenge facing tiger reserves in India is the isolation of the species ( Panthera tigris ) into 30 to 40 groups of discontinuous tiger populations across six major landscape complexes. A degree of isolation can lead to the evolution of local races.
The tiger has a very wide ecogeographic range in Asia and several, zoologically identifiable subspecies have been recognised. Again, if the “source population” is isolated, but the environment is artificially rendered favourable by man, then such a situation becomes conducive to the multiplication of same and similar genotypes beyond the carrying capacity of the particular area. This appears to be the case of the fluctuating tiger population in India: 2,000 in 1998, 1,411 in 2006, 1,706 in 2010 and 2,226 in 2014. The interphase increase in the tiger population may not guarantee its conservation. Therefore, the chief hurdle is inbreeding on account of fragmentation. One way to increase the genetic base is to have corridors between tiger reserves, so as to help in gene flow. But this is not practical due to a paucity of land. The only alternative left is in the introduction of a genetically viable tiger population from other habitats to widen the extent and nature of genetic diversity and which can be done based on data from genetic fingerprinting across reserves.
The dictum “it all depends on the green” was perhaps forgotten in the earlier programmes of conservation in India, which began with “big cats and large mammals” due to their top position in the food chain. The “tiger-deer-grass-water” link is too simplistic a relationship to be applied to the spectrum of diversity and ecosystems. In situ conservation has to be attempted on a holistic basis, taking all forms of data into account. In the ultimate analysis, it is genetic diversity that matters. India, once a tiger land, and now spending crores on ‘Project Tiger’, should now make an attempt to focus on the importance of diversity in the science of saving tigers.
A.N. Henry,Coimbatore
