Niche separation in sympatric lion-tailed macaques (Macaca silenus) and Nilgiri langur (Presbytis johnii) in an Indian tropical rain forest

Abstract

The study was carried out on one group each of lion-tailed macaques and Nilgiri langurs living as sympatric groups in a rainforest in Anaimalai Hills, Western Ghats, south India. Whereas the lion-tailed macaques were found to be frugivorous/ insectivorous, the Nilgiri langurs were primarily folivorous. Fruit was the only shared component in the diet of the two species. The lion-tailed macaques occupied a higher substratum than the Nilgiri langurs not only for their routine activities, but also for overall feeding and fruit feeding. The presence of lion-tailed macaques resulted in further lowering the feeding substratum and increased passivity in Nilgiri langurs. Food specialization and vertical stratification differentiate the niches of these two sympatric species.