The hilly terrain of the Western Ghats, Mudumalai (the ancient hills) is made most attractive wildlife reserve because it is clothed in dense mixed and moist deciduous forests. Moyar River, which separates Mudumalai from Bandipur runs through the Park following its course runs the Mysore-Ooty highway. The hilly terrain, with just 321 sq. km. in area, provides diverse habitats. The wild elephant, gaur, deer and primates like the bonnet macaque and langurs all inhabit the Park. The predators include the tiger, leopard and the dhole - the Asiatic wild dog, that hunts in packs. The predators of the skies are the crested hawk eagle and the crested serpent eagle that can be seen circling above.

Among the stands of teak and bamboo thickets, in the cool of the dense forests, are colourful birds - hornbills, the great black woodpecker with its dramatic red crest, mynas, barbets and parakeets. The tiny eared owl, the scops owl and the little scops owl are more heard than seen.

The Annamalai Sanctuary, lying adjacent to Mudumalai isolated for two species that are exclusive to it - the Nilgiri langur and the lion tailed macaque.