Assessing tiger prey and factors influencing tiger abundance in the Sundarbans

Monitoring prey species is crucial for tiger conservation, particularly in the Sundarbans, where prey diversity is limited. This study assessed the status of tiger prey species and examined the relationship between tiger and prey abundance using tiger pugmarks and prey pellet counts under a unified sampling framework. We established a total of 808 pellet sample plots (200 m 2 each) and conducted 1286 km boat-based transect to collect data between 2021 and 2023. The mean pellet group densities of Spotted deer ( Axis axis ) and Wild boar ( Sus scrofa ) were 295.09 and 27.21 pellet groups/ha, corresponding to densities of 35.44 and 15.75 ind./km 2 , respectively. The mean number of tiger pugmark set was 0.47/km of river courses travelled, with reasonable variation across east-west forest regions that closely aligned with the latest tiger density estimates. The generalized linear model revealed a significant positive relationship between Spotted deer and tiger abundance, while the relationship between Wild boar and tiger abundance was positive but not statistically significant. In contrast, human disturbance and reserve forest had negative impacts on tiger abundance in the Sundarbans. This study presents a cost-effective method for monitoring tigers and their prey, and offers valuable insights into predator-prey dynamics within the fragile ecosystem of the Sundarbans. Furthermore, our findings underscore the critical role of Spotted deer in sustaining tiger populations and highlight the need to strengthen protection strategies not only for sanctuaries but also for the reserve forests of the Sundarbans.