The celebrations unfolding about 16% increase in tiger numbers (to 1,706) across the country deserve a closer look. To demand such scrutiny is not to deny the essential fact that the central government and some of the states have taken important steps to conserve tigers after the debacles of 2004-2006. The prime minister's Tiger Task Force (TTF) of 2005, which despite its many limitations, clearly recognized the importance of "inviolate", well-protected tiger habitats of substantial size, and, strongly endorsed application of modern wildlife science to monitor tiger populations is a good example. Building on foundations laid by TTF, the National Tiger Conservation Authority (NTCA) has substantially increased funding for voluntary village relocations, curbed some runaway development projects around tiger reserves, and laudably opted to switch over to tiger reserve patrolling by local community-recruits rather than paramilitary forces.
On the other hand, pressures from rural land uses, mega projects, and poaching of prey and tigers, remain serious threats. The jury is still out as to what has worked and what has not: tiger populations can collapse rapidly but take years to rebound. The critical question is: can the new tiger numbers reliably inform us about the impact (or otherwise) of our conservation efforts at a scale that really matters – the fate of individual local tiger populations?
One recommendation of TTF was that tiger monitoring should be based on modern animal population sampling methods rather than on the discredited 'pugmark census'. The second was that monitoring methods imbibe peer-reviewed science and involve non-governmental expertise. Although the first recommendation was implemented in 2006, the new survey method was the brainchild solely of the government-run Wildlife Institute of India. This survey – labelled as phases 1 to 3 of the national tiger estimation – generated a figure of 1,411 tigers. Immediately, the media quite unjustifiably proclaimed a huge tiger decline by comparing this estimate to the earlier arbitrary figure of 3000 tigers from the invalid pugmark census. While NTCA weathered this storm of criticism, a description of the new methodology was not published in a peer-reviewed scientific journal until 2010 when, a partial description appeared.
An internationally recognized biostatistician opted out of this publication, citing fundamental scientific differences. However, other components of the 2006 survey results such as total number of tigers photo-captured and clear examples of extrapolation of these to wider landscapes remain unpublished to this day. Although 2010 survey does report 615 tigers were photo-captured, the overall methodology remains opaque. Therefore, clarity about the central claim that tiger numbers have increased by 16% while tiger habitat occupancy has shrunk by 25% during the last four years must await further data transparency.
However, my main concern is more fundamental. A global analysis (http:// www.ncbi. nlm.nih.gov/pmc /articles/ PMC2939024) in which I was involved shows 70% of the world's surviving tigers now occur on only 6% of remaining habitat. These sources are the only well-springs that can repopulate the empty surrounding tiger landscapes. They should be the 'inviolate' areas for focused protection. Broad patterns of the two WII tiger surveys indeed show similar source-sink patterns prevail in India. Forty-odd tiger source populations harbour most of our viable tiger populations. Each population is like a patient in an intensive care ward: it needs intensive photographic or DNA monitoring, not just once in four years, but year after year. Is this a practical goal? Our Centre for Wildlife Studies (supported mainly by Wildlife Conservation Society, New York in collaboration with NTCA and state forest department) has implemented such monitoring of tigers in Karnataka over 20,000 sq km. For several years, we have camera-trapped 3000 sq km area. In contrast, WII surveys covered 10,000 sq km spread across 100,000 sq km area across the whole country, just once in four years.
On a positive note, technical consultations which began two years ago among scientists of Wildlife Conservation Society, WII and NTCA, have already yielded a common protocol for future intensive camera-trap surveys, identified as Phase 4 by the TTF. Such annual camera trap-surveys will cost no more than the present surveys. But they can help us track the fate of individual populations and even of many individual tigers.
Therefore, rather than celebrating these uncertain national tiger 'increases' (or for that matter bemoaning 'decreases' like we did in 2006) tiger conservationists need to move on. It took the MoEF 25 years to switch from the 'Pugmark Census' to the present phases 1-3 of sample surveys. I worry that if the next a course correction to reach Phase 4 takes years to unfold, the cost will be paid in the form of more Sariska-like local extirpations of tigers. Therefore, I prefer to reserve the celebratory option to the cricket field, rather than to the national tiger recovery proclaimed based on these new tiger numbers.
(The author is senior scientist, Wildlife Conservation Society)