Lion tailed macaque (Macaca silenus) in its habitat.
These primates are different from Nilgiri langurs, common langurs and bonnet macaques in their dietary habits. Lion-tailed macaques can't digest leaves. Digestion of leaves requires a different composition of the stomach where the cellulose can be broken down by microbes. Their simple stomach can easily digest their diet of fruits, seeds, resins and insects.
Canon EOS 1D Mark IV, Canon EF 400mm f2.8 L IS USM, ISO 800, f16, 1/50, full frame image.
Look forward to your comments and critiques.