Numerous small patches of forests, known locally as sholas, occur in hollows and gullies. Predominant species include Eulalia phaeothrix , Ischaemum indicum , Arundinella fuscata , Tripogon bromoides , Tripogon ananthaswamianus and Sehima nervosum . There is thick cover of the shrub Strobilanthes kunthianus in some areas. Taller shrubs and grasses such as Chrysopogon zelanica, Strobilanthes kunthianus , and Eupatorium glandulosum often occur on the slopes and cliff bases. Tahr usually occur in large groups of up to 150 animals and generally inhabit the fringes of the grassy plateau, making use of the bordering cliffs, rocky slabs and slopes for refuge and parturition.
Leopard occurs in both the spotted and black phases.
The Nilgiri tahr at Eravikulam has been the subject of various general studies and surveys, which are referred to in Anon. The sanctuary was originally created to conserve the largest known wild population of Nilgiri tahr. The habitat has been extremely well preserved and, as increasingly more grassland is annually converted to wattle and eucalyptus plantations, it may become the last relatively intact representative of the plateau grassland ecosystem of the Western Ghats. A rotational system of controlled annual burning to provide fresh grass for the Nilgiri tahr seems to be beneficial. Sambar and gaur are usually hunted with firearms whilst tahr is also hunted with the aid of domestic dogs or, especially near human settlements, wire snares.