S.M. Saiful Islam Kabir,  Sundarbans

The world’s largest mangrove forest and a biodiversity-rich coastal region of southwestern Bangladesh—known as the Sundarbans and often referred to as a “fish treasury”—is home to 375 species of wildlife. Among them, five species—deer, monkeys, wild boar, porcupines, and monitor lizards—are considered primary prey of the Royal Bengal Tiger.

Preliminary findings from an ongoing camera-trapping survey suggest that the tiger population in the Sundarbans is increasing. A recent survey conducted with the support of the International Union for Conservation of Nature (IUCN) also confirms a rise in the populations of these five prey species.

According to the Sundarbans Forest Department, the forest, which is periodically flooded by saline tidal water, harbors 375 species of wild animals. However, only five of these species are recognized as primary food sources for the Royal Bengal Tiger: deer, monkeys, wild boar, monitor lizards, and porcupines.

From November 2021 to December 2023, a comprehensive survey was conducted on these five species with full support from the IUCN. The results show significant population growth across all five.

For example, in 2004, the estimated population of spotted and Maya deer was 83,000. That figure has now risen to 136,604.

The monkey population has increased from 51,000 to 152,444, and the wild boar population from 28,000 to 47,515.

Monitor lizards, included in the survey for the first time, number 25,124, while porcupines have been recorded at 12,241.

In total, these five prey species now number 373,928 individuals in the Sundarbans.

Khulna Regional Forest Conservator Mihir Kumar Dey said , tere is now a sufficient prey base for tigers in the Sundarbans. Due to the forest being free from bandit activity, smart patrolling, and strict monitoring by the Forest Department, RAB, and Coast Guard, the hunting of deer and other wild animals has significantly declined.”

He added that expanding the protected sanctuary area to 51% of the forest has contributed to a more favorable environment, leading to a surge in the prey population. This is also the first time the numbers of monitor lizards and porcupines have been officially recorded.

Encouragingly, preliminary data from the ongoing camera trap survey also shows a rise in the tiger population. The final results of this survey will be published on July 29, marking Global Tiger Day, when the exact number of Royal Bengal Tigers in the Sundarbans will be officially announced.

The survey was financially supported by KfW Development Bank of Germany and conducted in partnership with IUCN.