Tiger decline caused by the reduction of large ungulate prey: evidence from a study of leopard diets in southern India

Populations of leopards and tigers in the Kalakad-Mundanthurai Tiger Reserv e, India, appear to be declining. To identify the cause of this decline, we examined the diets and the relative densities of leopards and tigers, comp aring seat from this park with that from the Mudumalai Wildlife Sanctuary, a park known to have high leopard and tiger densities. Results suggested th at the leopard density in Mudumalai was approximately twice that in Mundant hurai. No evidence of tigers was found in Mundanthurai. Prey species found in leopard diets in the two parks was similar; albeit, mean prey weight and the proportion of large ungulates were markedly lower in the Mundanthurai leopard diet. These dietary differences are consistent with the infrequent sightings of large ungulates in Mundanthurai. Analyses of satellite data re vealed that large areas of grazing land in Mundanthurai have shifted to thi cket, reducing available forage for large ungulates. Since large ungulates constitute important tiger prey, the low density of ungulates in Mundanthur ai might explain the apparent absence of tigers. Our findings suggest that the tiger population in the Kalakad-Mundanthurai Tiger Reserve could be enh anced via the application of habitat management for large ungulates. (C) 19 99 Elsevier Science Ltd. All rights reserved.