The Sunderbans might be having almost as many tigers as the forests can accommodate and that is possibly the reason for the rise in the number of big cats straying near human habitats.
The Wildlife Institute of India, entrusted with preparing a report on the surge in human-wildlife conflict in the mangrove delta, has told as much to the state forest department.
“In the hostile Sunderbans terrain, the carrying capacity is three to five tigers per 100sq km. In multiple forest blocks, the density is more than three tigers per 100sq km,” Qamar Qureshi, a senior scientist with WII who is involved in preparing the report on the rise in straying incidents, told The Telegraph.
The findings are based on the results of the national tiger census of 2018, which had pegged the number of big cats in the Sunderbans at 88. The 2020-21 census that was conducted by the state forest department had found 96 tigers in the mangrove delta.
The Sunderbans is spread across 10,000sq km, a little above 4,000sq km of which is in India. The rest is in Bangladesh. The Indian Sunderbans is split between the tiger reserve and the South 24-Parganas division.
The 2014 national census had counted 76 big cats in the mangrove delta. The Sunderbans leg of the 2022 national tiger census started in the first week of December.
“The rise in the number of tigers could be the reason for the rise in straying incidents. When there are too many tigers in one forest, the young adults might be forced to move out in search of new territories. The weaker ones might also look for a new home,” said Qureshi.
At least eight tigers have strayed near villages in the Sunderbans since December 2021. All of them were captured and released into the wild. So far, no human casualty has been reported.
The preparation of the final report will take a couple of months. For now, the WII has advised the state forest department to release Sunderbans tigers that are captured after they stray near villages in those forests in the delta that have a comparatively less density of the tiger population.
“Based on the advice, we have released three tigers captured in the past few days in a forest compartment called Chamta, inside the National Park East range of the Sunderbans Tiger Reserve. The WII has identified Chamta as a forest block with a really low density of tiger population,” said Tapas Das, field director of STR.
A retired forest official said sending tigers to a forest different from where they came was fraught with risks.
“A decade ago, straying tigers from other forests were released into the Ajmalmari forest. More than one tiger tried to go back to its original home and kept wandering many kilometres,” said the official.
A section of serving and retired officials said the “optimum carrying capacity” was not a static concept.
The peak density depends on several parameters like prey base, human interference and male-female ratio of the tigers in a forest, they said.
“The assumption that three to five tigers is the optimum range dates back to 2018, in keeping with other parameters from four years ago. Since then, the mangrove delta has been ravaged by multiple storms. The pandemic has multiplied manifold the human interference in the forests. There is no reason to believe that the parameters in 2022 should be the same as 2018,” said another official.
The pandemic triggered the homecoming of hundreds of thousands of villagers who used to work across the country. The loss of livelihood has forced many of them to turn to the forests for fish and crabs.
Over 30 people have been killed in tiger attacks inside the forests since the summer of 2020. In many cases, villagers enter forests after breaching the nylon nets marking their boundaries, making it easier for tigers to come out.
Debal Ray, chief wildlife warden of Bengal, said the ploy to release stray tigers into forests with lower density of the big cat population was the “best possible option to reduce human-wildlife conflict”.
The findings of the current census will be ready for our use only after a few months. Till then, we have to go by the findings of the last census,” he said.