Diet and prey profiles of three sympatric large carnivores in Bandipur Tiger Reserve, India

摘要

We conducted a field study of diets of three sympatric large carnivores, the tiger Panthera tigris, the leopard Panthera pardus and the dhole Cuon alpinus in Bandipur Tiger Reserve, India, based on analyses of 381, 111 and 181 scats, respectively. The frequency of occurrence of prey items in scats was converted to relative biomass and number of prey consumed using regression equations based on earlier feeding trials. The results showed that although these predators kill ~11-15 species of vertebrate prey, relatively abundant ungulate species provide 88-97% of biomass consumed by them. Although the dietary niche overlap among the three species was high (Pianka's index of 0.75-0.93), some specialized predation was observed. The largest ungulates, gaur Bos gaurus and sambar Cervus unicolor, provided 73% of biomass consumed by tigers, whereas medium-sized chital Axis axis and wild pig Sus scrofa formed 65 and 83% of the biomass intake of leopards and dholes, respectively. In terms of the relative numbers of prey animals killed by the three predators, chital, which is the most abundant prey species, dominated their diets (tiger=33%, leopard=39% and dhole=73%). The results of the study, in conjunction with earlier work, support the prediction that abundance of ungulate prey species, as well as their availability in different size classes, are both critical factors that facilitate sympatry among the three predators.