Both sanctuaries are situated in an extensive preserve; latter declared as a 'project tiger reserve'.

Kalakkadu is situated in an area of 223 sq. km in Tirunelveli district including the foot hills of Western Ghats and adjoining area. The flora ranges from tropical wet evergreen to tropical dry decideous and thorn forest at down-hills. Lion-tailed macaque, nilgiri langur, bonnet macaque and common langur, nilgiri tahr, sambar, sloth bear, gour, elephant, tiger, flying squirrel and panther wild dog form some of the wildlife that can be seen in this sanctuary.

Mundanthurai, near the Kerala border, has had it's pristine state altered by 7 major dams and large hydro-electric pipes that intersect the landscape. Principally, it is a tiger sanctuary though it is also noted for chital, sambar and the rare lion-tailed macaque.