Monday, March 28, 2011


The latest Tiger estimation report released on 28-3-2011 reports an increase in adult tiger numbers to 1636 (1706 including Sunderbans). The previous estimate of 2007 was 1411 tigers. This is an increase of 16% compounded over 4 years. This tantamount to the view that the previous decline of tigers has been reversed. The threats faced by tigers have not diminished in last four years. It has gone up is some areas. So it is a wee bit difficult to digest the claimed reversal of the decline of tigers. There is an urgent need to evaluate full details of how these tiger numbers have been arrived at.

I found the response by Dr Ullas Karanth to the National Tiger Estimation Report very germane. It hits the nail on the head.

Dr Ullas Karanth says “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 4of 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”
Dr Ullas Karanth goes on to add “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 decadesdespite 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.”

Here is my view on this .Remember the Amur tiger report published in Mammalian Biology recently? The researchers said the Amur tigers have been reduced to an effective population of fewer than 14 animals even though approximately 500 Amur tigers live in the wild. Genetic bottleneck during the tigers' recent history has been brought out by the research. Mode shift in allele frequencies tests were positive, while the M-ratio test was negative, indicating the likelihood of a contemporary rather than a historical population bottleneck.  Against the backdrop of this the suggestions by Dr Ullas Karanth assumes great significance.

I fully endorse the view of Dr Ullas Karanth that to achieve real progress in Tiger monitoring, 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.  

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