With an Indian Statistical Institute (ISI) analysis raising doubts over the number of tigers in the Sunderbans, a fresh census of the big cat will be conducted this winter.

“A tiger census will be conducted in Sunderbans in winter after three years although dates are yet to be finalised,” Director of Sunderbans Biosphere Reserve (SBR) P. Vyas told PTI here.

The Indian Statistical Institute (ISI) which was asked by the West Bengal government to develop a software programme to process field data on tiger pugmarks, had claimed in July 2006 that there were only 75 tigers in the Sunderbans, a World Heritage site.

The state’s Chief Wildlife Warden S.B. Mondal, however, told PTI that the last census had put the tiger count at 274.

The ISI, he said, was entrusted with developing software for which it was given data of a few ranges. “Their claim that there are only 75 tigers is wrong.”

The Wildlife Institute of India, he said, was supplied data in 2006, but was yet to give the tiger count.

Meanwhile, the SBR director said, the census would be done on the methodology developed by the Project Tiger of the Government of India, besides radio collaring and collection of DNA samples of tigers at the Sunderbans.

It was planned to radio collar six tigers, Mr. Vyas said.

SBR sources said tiger estimation has been traditionally done in the Sunderbans by the ‘pug mark method’ in which the fresh impressions of the left hind pug were collected from the field and analysed.

The pugmark method was field friendly, but due to drawbacks, Project Tiger had developed a new methodology for monitoring tigers, co-predators, prey and habitat, the sources said.

The last census was conducted in the Sunderbans in 2001 that put the tiger population at 274, but since it was disputed in the ISI software analysis, the 2006 one was stalled.

Wildlife experts also disputed the forest department’s claim and said that the number of tigers would be much less than what was claimed.

Wildlife NGO, ‘Nature, Environment and Wildlife Society’, Secretary Biswajit Roy Chowdhury, who has long experience of working in the Sunderbans, said that the number would not be more than 100 to 110.