The Range of Prey Size of the Royal Bengal Tiger of Sundarbans

Relatively little is known about the feeding habit of the Royal Bengal Tiger of Sundarbans and the relative biomass of individual prey base species that the predator consumes during each kill. This is the first attempt to collect such data from the study area. Data sets of two phases have been used. Identification of undigested remains of 214 tiger scat samples was carried out. A comparison with Sundarbans tigers in zoo has been made. In its natural habitat, the tiger consumes more of spotted deer, followed by wild boar, rhesus monkey, and water monitor. Though the tiger consumes a relatively low proportion of small prey species to meet its dietary requirements, it gains importance in the present perspective. Significant increase is noted in the relative number of prey species consumed in the second phase, which correlates well with increased prey availability. Hypotheses formulated to find the difference in prey biomass and relative number of prey consumed have been tested statistically. A significant difference in terms of relative number of prey consumed only was derived which has been qualitatively correlated with the positive effect of increased vigilance, as revealed by secondary data, on conserving tiger habitat vis-a-vis the increased prey availability in Sundarbans. 1. Introduction As with all other organisms, the tiger’s diet is a fundamental aspect of its ecological niche. Quantifying diets has long been and continues to be one of the first steps in studying a species’ basic ecology as discussed by Sih and Christensen [1]. For the community ecologist, forager diets potentially play a central role in determining the predator-prey interactions and dynamics of competition between species [2, 3]. The availability and range of diet play a pivotal role in determining the dynamics of competition at inter- and intraspecific levels, predator-prey interactions, and other community interactions. An understanding of diets, and ideally, an ability to predict diet shifts in response to changes in prey biomass or prey availability are thus major issues, especially in conservation and management affairs. The tiger is always found to be associated with large mammalian herbivorous prey species in all its habitat ranges across the globe. These include wild buffalo (Bubalus bubalis), gaur (Bos gaurus), nilgai (Boselaphus tragocamelus), swamp deer (Cervus duvaucelii), sambar (Rusa unicolor), barking deer (Muntiacus muntjak), spotted deer (Axis axis), and wild boar (Sus scrofa) [4–8]. But according to Schaller [4], occasionally they have been found to predate on