The Grizzled Squirrel Wildlife Sanctuary, commonly known as the Srivilliputhur Wildlife Sanctuary mainly aims on protecting the grizzled giant squirrel, and was initiated in the year 1988. The sanctuary covers about 485.2 square kilometers of the southwest boarder of Periyar Tiger Reserve. The sanctuary is also well known as the best preserved forest in the south region of the Palghat Gap.
The 485 square kilometers in the western region of Tamil Nadu is occupied by the sanctuary. It is located by the eastern water shed of South India in the Western Ghats. The sanctuary posses a number of high hills, many valleys and also large numbers of peak, with a maximum height of 1,800 meters.
The sanctuary is located in the Srivilliputtur district covering Virudhunagar and partially occupying the district of Madurai. The sanctuary is guarded by the Andipatti hills in the north and the Tirunelveli district in the south. The eastern part of the sanctuary is occupied by Srivilliputhur district and Rajapalayam town and in western region we have the Theni District and Theni Town. The sanctuary also serves as the eastern region of the Periyar river watershed. The sanctuary is placed to the Periyar Tiger Reserve, from the former’s south western region. From the north western point of the sanctuary, it is near to the Megamalai Reserve Forest and Sivagiri Reserved Forest from the southern region.
Even though, the sanctuary mainly concentrates on the well being of grizzled giant squirrels, many other animals are also protected and cared in this sanctuary, like the common langur, barking deer, flying squirrels, leopard, mouse deer, bonnet macaque, elephants, lion tailed macaques, guar, nilgiri langur, Indian giant squirrel, nilgiri tahrs, slender lorris, spotted dear, palm civets, sloth bear, wild cats, tree shrew, wild boar, sambhar and spotted dear.
There are many numbers of resident and migrating elephants in the sanctuary and is a common sight. According to the data based on the wildlife census of the year 2002 shows the total number of elephant in the sanctuary as 256. The 2009 census shows that, the number of grizzled squirrels in the sanctuary has increased from the 2008 census. 30 lion tailed macaques were sighted in the sanctuary during its annual census, and in the year 2009 the number hiked to 45, which includes a number of young lion tailed macaques. These lion tailed macaques were spotted between the Nagariyar and Periyankavu. Groups of Nilgiri Tahr had been spotted at different regions of the sanctuary, like the Kottamalai region in the Rajapalayam town, Perumal Malai and Sathuragiri Hills, in the region near to the Sundara Mahalingam temple situated in Saptoor. The 2009 census reports shows the presence of a tiger in Sathuragiri.The number of tahrs in the sanctuary has increased to about 220 in the 2011 census.
The sanctuary has been marked as an important birds area and about 200 species of birds had been found in the area, from which 14 species of birds like the broad tailed grass warbler, the long billed vultures, red faced malkoha, nilgiri wood pigeons, white backed vulture, and the white bellied shortwing are the natives of the Western GhatsGhats. The sanctuary also protects almost endangered species like the Nilgiri fly catcher, the great pied hornbill, black-orange fly catcher and the Nilgiri pipit. The raptors dwelling in the sanctuary includes hawks, serpent eagles and black eagles. A bird census conducted in the sanctuary in the year 2013, showed that rare native species which are found in the higher altitudes of Western Ghats like, the great Indian and Malabar pied horn-bills, Sri Lankan frog mouth, mountain and green imperial pigeons, Rufus bellied hawks and eagles, residing in the sanctuary. Fewer number of rare migratory birda were also spotted like the Eurasia sparrow hawk, blue-capped rock-thrush, and the steppe eagle.
The forest of the sanctuary is a geographical combination of tropical evergreen forest, dry deciduous forests, semi evergreen forests, moist mixed deciduous forests, cultivated land and grasslands. In the Thaniparai region, the sanctuary occupies a Medicinal Plant Conservation Area. The Paliyar tribe residing in the sanctuary makes use of 69 herbal plants in the area which belongs to 58 different taxa and 42 different families, in order to treat 15 ailments.