Challenging the methodology employed for the latest tiger census, tiger expert Ullas Karanth has called for making public the “raw field data from Phase I, II, and III” of the 2014 tiger count for arriving at the real numbers.
Recently, researchers from the University of Oxford, Indian Statistical Institute, and Wildlife Conservation Society had questioned the methodology and warned of erroneous results.
However, National Tiger Conservation Authority (NTCA), which released the data, stood by its report.
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Mr. Karanth said raw field data were used for ascertaining the tiger numbers in 2006, 2010, and 2014.
The data belonged to public domain and there was no justification for hiding them from scientists, said Mr. Karanth told The Hindu .
Mr. Karanth said he was “not disputing that tigers numbers have increased in many locations in India in last eight years because of good work done by some States, such as Karnataka and Kerala, but the method employed to measure this is not sufficiently robust to measure changes at regional and countrywide levels.”
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NTCA report
The Status of Tigers in India report, 2014, released by the NTCA, had put the big cat population at 2,226 — a 30 per cent increase from the 1,706 of 2010.
“The overall methodology or its results have not been reviewed and published in any high quality scientific papers, except for one paper in 2011 which covered only one component of the methodology. The basic premises of that paper have been questioned.
The results of theses surveys appear anomalous and not reproducible,” said Mr. Karanth.
“The 30 to 40 major source populations in tiger reserves hold over 90 per cent of all our tigers.
Annual rigorous monitoring of these populations using the protocols prescribed by NTCA can yield more accurate tiger numbers, measure increases and decreases, and survival rates, which are essential to rigorously monitor our tiger populations. First priority should be to ensure that this accurate protocol is followed everywhere,” he said.
The Wildlife Conservation Society, in collaboration with the Kerala Forest Department, had in 2013, estimated the tiger density of Wayanad as 10.7 tigers per 100 sq km, which was comparable to the adjacent Nagarhole and Bandipur.
In Wayanad
The estimated mean population size was 42 tigers, which was accurate.
The latest estimate of 76 tigers in Wayanad might be the outcome of a flawed study conducted earlier, where substantial overlap of individual tigers with Bandipur and Nagarhole were not considered, he said.
Report showed a 30% increase from 2010
Karanth doubts overlap of tigers in Bandipur, Nagarhole
Make public raw field data of last year’s tiger count: Ullas Karanth