Nagarahole Tiger Reserve is an abode for variety of faunal species ranging from top predators like tiger, leopard and wild dog to mega herbivores like elephants and Guar to lesser known species like Palm civet, Mouse deer, flying squirrel and common otters. Presence of large area of wood lands support the co-existence of top predators like tigers (present on ground) and leopards (takes shelter on tree top). Further, difference in the prey selection between tiger (prefers large body size prey like Sambar, Guar and elephant calves) and leopard (prefers small body size prey like chital, wild pigs, langur etc,) have made the top predators to co-exist at very high density (11.9 tigers/100 sq km in 2010) and thus shaped the community structure of Nagarahole ecosystem for which it has been declared as tiger reserve in 2007.
Nagarhole has the highest congregation of Asian elephant in the world (at Kabini back water)
Having good density of elephant population (1Elephant/sq km) with connectivity on all sides, Nagarahole become an important place for the long-term conservation of Asiatic elephants and thus included under the larger Mysore elephant reserve. Further, with the scarcity of water and grasses during summer in the majority of places, there will be seasonal migration of elephants from Nagarahole-Bandipur-Mudumalai-Wayanad Tiger Conservation Unit (TCU) towards the Kabini back water, where the world's largest congregation of Asiatic elephants takes place. Thus, Kabini back water along the Kakankote area of DB Kuppe wildlife range become important place for conservation of Asiatic elephants and a dream place for wildlife viewers.
The vegetation pattern of the Nagarahole tiger reserve ranges from rich moist deciduous forest in the west to dry deciduous forest and thorny scrub forest in the east, interspersed with marshy-swamp valleys called Hadlus that acts as an unique habitat, best suited for wide range of wild lives. Thus, Nagarahole vegetation holds one of the best herbivore biomass per unit area in India, which in turn could support a healthy carnivore density (11.9 tigers/100 sq km in 2010).