A pair of spotted deer graze on the grassland on the banks of Bidyadhari river in Sunderban National Park in West Bengal. The meagre grasses that grow on the banks of the salty rivers and rivulets in Sunderban is important for sustenance of various critters, including the spotted deers who have adapted to the riverine ecosystem of the Sunderbans. The spotted deers and other herbivores in turn form a part of the food chain for the mighty royal bengal tigers.