A fortnight from now, more than 1,400 cameras will be installed at strategic locations across the Sunderbans forest to capture images of its apex predator.

The trap cameras will be in place for around 45 days as part of the annual tiger estimation exercise in the world’s largest mangrove habitat for the big cat.

The annual exercise is conducted by the forest departments of the states that have tigers in the wild. The national tiger census, a quadrennial exercise, is conducted by the National Tiger Conservation Authority, which functions under the Union government.

This is the first time the cameras will be placed simultaneously in the Sundarban Tiger Reserve (STR) and the South 24-Parganas forest division. Usually, the cameras are placed in a phased manner.

“The exercise begins on November 21. Usually, we used to keep the cameras for around 30 days. This year, the cameras will be in the forests for 45 days to capture as many images as possible.... We are expecting to complete the installation of the cameras by November 26. They will remain in place till the first week of January,” said Justin Jones, deputy field director, STR.

In total, 1,444 all-weather night-vision cameras will be placed in 722 strategic locations called grids — each 2sqkm grid will have a pair of cameras placed in opposite directions.

The Sunderbans is spread across 10,000sqkm, a little above 4,000sqkm of which is in India.

The Indian Sunderbans is split between the STR and the South 24-Parganas forest division.

“The camera images will be analysed with the help of a software to get to a number. After that, the number will be cross-verified by ocular (visual) estimation,” said Jones.

The final report of the last national count, “Status of Tigers 2022”, was released by the National Tiger Conservation Authority on July 29 (International Tiger Day) 2023. The exercise had pegged the number of tigers in India and the Sunderbans at 3,682 and 101, respectively.

In 2020-21, the state-level exercise pegged the number of tigers at 96 in the Sunderbans, the world’s only mangrove tiger habitat.

But after that, the state forest department stopped formally releasing the results of the annual count.

“The count is for internal analysis. The authoritative figures are only released by the NTCA. We can do ocular estimation but the clear estimation protocols are established by the NTCA. That is the accepted standard for any estimation. The main objective of this annual
estimation is to gauge the impact of the tiger protection and habitat management steps we have been taking,” said an official at Aranya Bhavan, the state forest department headquarters.

But sources in the department said the number should be more than 105. The estimation excludes cubs. Only tigers more than a year old are included in
the count.

“The annual state-level exercise is just an estimate of the tigers based on the findings of the trap cameras. In comparison, the national count is a much bigger and more detailed exercise,” said Nilanjan Mallick, director of the Sundarban Biosphere Reserve, which includes the STR and the South 24-Parganas division.