The hills are located at the north-west of the Western Ghats and the westernmost edge of the Eastern Ghats. Thus this area supports a diverse flora and fauna in view of the various habitat types present. A wildlife sanctuary of was created around the temple on 27 June 1974, and enlarged to on 14 January 1987. The sanctuary derives its name Biligiri from the white rock face that constitutes the major hill crowned with the temple of Lord Ranganathaswamy or from the white mist and the silver clouds that cover these hills for a greater part of the year. An annual festival of Lord Vishnu, held in the month of April, draws pilgrims from far and wide. Once in two years, the Soliga Tribals present a 1-foot and 9 inches slipper, made of skin, to the deity in Biligiriranga Hills. The hills are in the Yelandur, Kollegal and Chamarajanagar talukas of Chamarajanagar District of Karnataka. They are contiguous with hills in Sathyamangalam Wildlife Sanctuary in Erode District of Tamil Nadu to the south. By road, they are about from Mysore and from Bangalore. The road leading to the villageon top of the hills may be approached either from Yelandur or Chamarajanagar. Kyathadevara Gudi or K Gudi is located close to BR Hills, where safari is conducted.
Geography
The BR hills is starting point Eastern Ghats and contacts with border of the Western Ghats allowing animals to move between them and facilitating gene flow between populations of species in these areas. Thus, this sanctuary serves as an important biological bridge for the biota of the entire Deccan plateau. The BR hills along with the Male Mahadeshwara Hills range forms a distinctly unusual ridge running north–south amidst the plains of Bangalore, Mysore and Krishnagiri. The peaks of these lofty ranges rise as high as 1800 m. The highest hill is Kattari Betta, at 1800 metres. Various observations point to a possible biogeographic link between BR hills and Nilgiri ranges. Biogeographically, the sanctuary is unique. It is located between 11° and 12° N and the ridges of the hills run in the north–south direction. It is a projection of the Western Ghats in a north-easterly direction and meets the splintered hills of the Eastern Ghats at 78° E. This unique extension / offshoot of Western Ghats constitutes a live bridge between the Eastern Ghats and Western Ghats with the sanctuary located almost in the middle of this bridge. Thus, the biota of BRT sanctuary can be expected to be predominantly of Western Ghats in nature with significant proportion of eastern elements as well.
Climate and vegetation
The sanctuary, ~35 km long north–south and ~15 km wide east–west, is spread over an area of 540 km2 with a wide variation in mean temperature and annual rainfall The hill ranges, within the sanctuary raise as high as 1200 m above the basal plateau of 600 m and run north–south in two ridges. The wide range of climatic conditions along with the altitude variations within the small area of the sanctuary have translated it into a highly heterogeneous mosaic of habitats such that we find almost all major forest vegetation types – scrub, deciduous, riparian, evergreen, sholas and grasslands. The forests harbour close to 800 species of plants from various families and shows a close affinity to the Western Ghats.
Flora and fauna
The Biligiris are Charnocktite hills, covered with tropical dry broadleaf forest, part of the South Deccan Plateau dry deciduous forests ecoregion. The forests range from scrub forests at lower elevations, degraded by over-use, to the tall deciduous forests typical of the ecoregion, to stunted shola forests and montane grasslands at the highest elevations, which exceed 1800 meters. The forests form an important wildlife corridor between the Western Ghats and the Eastern Ghats, linking the largest populations of Asian elephants and tigers in southern India. The most conspicuous mammals in the BR Hills are the herds of wild elephants. The BR hills is the only forest east of the main Western Ghats mountain ranges in the central southern peninsula to harbor these pachyderms in large numbers. The forests were the study area for R. Sukumar, a scientist who studied the elephants of the area in the early eighties. A recent survey has revealed the presence of 62 tigers in this sanctuary. The forests are well known for many gaur, the largest bovines. BR hills are a good place for viewing many other large and small animals. There are about 26 species of mammals recorded in the sanctuary. The other mammals include sambhar, chital, the shy barking deer which are quite common here and the rare four-horned antelope. Carnivores include tigers, leopards, wild dogs, lesser cats and sloth bears and among arboreal mammals two species of primates and three species of squirrels including the giant flying squirrel are recorded. A recent survey of tigers by DNA analysis of scat samples has revealed 62 tigers, although the number may be more. 254 species of birds recorded in the BR hills. These include the enigmatic southern population of the white-winged tit, a specimen of which was collected by R. C. Morris and now housed in the Natural History museum at Tring. A recently discovered species includes a microhylid frog Microhyla sholigari, named after the Soligas, an indigenous tribe that inhabit these hills.
Threats
in the fringes of the hills is rampant after the brief lull of activities during the time when the dreaded bandit Veerappan was on the run. After his death, the quarrying activities have taken off with renewed vigour with strong political backing. The forest department and the local NGOs were instrumental in banning disposal of plastic within the sanctuary.
