Dr. Ullas Karanth’s Response to the 2011 National Tiger Estimation Report
The result of the national tiger estimation exercise conducted over the past couple of years has been released on 28-3-2011. It reports an increase in adult tiger numbers to 1636 (1706 including Sundarbans), up from the previous estimate of 1411 tigers in 2007. This is an increase of 16% compounded over 4 years, suggesting that the previous decline of tigers has been reversed. However, since full details are not yet available as to how these tiger numbers have been arrived at, it is not possible to give an expert opinion about the new numbers. However, since various threats faced by tigers do not appear to have diminished in last four years, it is difficult to explain the claimed reversal of the decline of tigers.
Moreover, going beyond such country wide estimates, a more important issue needs to be addressed: Most of India’s reproducing tiger populations are now concentrated in 10% of all tiger habitat that holds 90% of all our tigers. These 40 or so ‘source populations’ are under grave threat and need to be ecologically monitored annually using intensive camera trapping (as prescribed in the proposed Phase 4 of the national estimation, which is yet to even begin). Monitoring of tracks by Forest Guards is not a substitute for such reliable monitoring using camera traps or DNA sampling as has already been proven earlier in places where tigers vanished even as guards did similar patrol-based monitoring. To me the most serious flaw in the present government effort is the basic futility of trying to generate all-India level tiger counts once in 4 years, even while ignoring critical task of intensively monitoring key source populations year after year.
The time has now come to switch from these once in five year national estimation (termed Phases 1 to 3) and focus intensive camera trap or DNA monitoring of tiger source populations so that we can track the fate of individual tigers, and estimate survival and recruitment rates to gauge how each of these populations is faring. If we do not shift to such focused, intensive monitoring approaches, we are at serious risk of losing more and more key populations even while we celebrate supposed ‘increases’ from these national counts (it is well known that half the tiger reserves lost most of their tigers in the past decades despite these national counts!).
On a more technical note, the full process of how these tiger numbers are generated for individual tiger populations and landscapes, has not been made public in a scientifically acceptable manner. Only one scientific paper, which explains only a part of this protocol, has been published in 2011, based on data from the last round of estimation in 2007. While this is not the place for a technical discussion, I see serious deficiencies in the methodology which has been published.
For several years Centre for Wildlife Studies has monitored tigers rigorously in Karnataka State over an area that holds about 15% of the country’s tigers. We camera trap a 3000 sq km area, every year, photographing more than 100 tigers in a population of about 250. On the basis of these data we believe that the tiger population in Karnataka is holding out, and even increasing in some areas like Bhadra and Kudremukh because of good work by government and NGOs. We believe that similar intensive monitoring of all key source populations can be easily done to generate similarly useful results across the country. This would not cost more than what the present ‘once in four year’ national estimation costs. However, to achieve such progress, government must give up its present monopoly over tiger monitoring and bring in outside expertise and resources in order to ensure greater reliability, transparency and credibility in monitoring the fate of our national animal. I hope this long delayed Phase 4 of tiger counting will happen before it is too late.