According to the latest camera-trap report conducted by the West Bengal forest department and WWF during November to March this year in Sundarbans, there are a minimum of 83 tigers and could be a maximum of 128.

"The mean of this range has been calculated at 86 using a statistical model. There has been a marginal increase in the tiger count so we can say that the population is now very well stable," Principal Chief Conservator of Forests and Chief Wildlife Warden Pradeep Vyas told PTI.

Since tigers are at the apex of the forest ecosystem, the stable population of the big cats prove that the delta's ecosystem is also healthy.

"Most importantly the population range is close to last year's range which proves the stability. There can be minor increase and decrease in the population," Vyas said.

In 2014 a similar exercise had put the number of tigers at 76.

"You can say that the population is stable. It is more or less the same since the last survey," said WWF's RatulSaha.

It was for the first time that cameras were set not only in the Sundarbans tiger reserve area but also outside it in the rest of South 24-Parganas forest division.