Dholes selectively preyed on adult male chital, whereas leopards did not. Tiger predation was biased towards adult males in chital, sambar and wild pig, and towards young gaur. The average weights of principal prey killed by tiger, leopard and dhole were, respectively, 91.5 kg, 37.6 kg and 43.4 kg. Tigers selected prey weighing more than 176 kg, whereas leopard and dhole focused on prey in the 30-175 kg size class. Gaur Bos gaurus were preferred by tigers, whereas wild pig Sus scrofa were under-represented in leopard diet, and langur Presbytis entellus under-represented in dhole diet. Predators showed significant (P < 0.05) selectivity among prey species. Ungulate and primate prey attained a density of 91 animals km-2 and comprised 89-98% of the biomass killed. Predator selectivity for size, age, sex and physical condition of prey was estimated using selection indices. Selectivity for prey species was inferred from likelihood ratio tests comparing observed counts of scats to hypothesized scat frequencies generated from prey density estimates using parametric bootstrap simulations. Carnivore diets were determined from analyses of scats (faeces) and kills. Densities of large herbivores were estimated using line transects, and population structures from area counts. Ecological factors influencing prey selection by tiger Panthera tigris, leopard Panthera pardus and dhole Cuon alpinus were investigated in an intact assemblage of large mammals in the tropical forests of Nagarahole, southern India, between 19.
0 Comments
Leave a Reply. |