The vast Indian subcontinent covers a wide variety of biomes, including : tropical, subtropical & montane forests, tropical & high altitude deserts, fresh water & marine ecosystems, estuarine forests and lagoons. As such, the area covered by the Indian subcontinent contains tremendous biodiversity and pockets of high species level endemism.

Although India suffers from massive overpopulation, protected natural areas remain islands of persistence for much of this biodiversity. Remarkably, despite the pressures on the land by the vast human population, megafauna like Asian elephants and Bengal tigers still occur in sustainable numbers.

Centres of high species richness and endemism that occur within India are largely restricted to the hill forests of northeast India, central Himalayas, the Andaman and Nicobar Islands and the Western Ghats.

Western Ghats Biodiversity

The Western Ghats are an ancient range of mountains that run parallel to the west coast of Peninsular India, from the southwestern tip of India in Kerala and Tamil Nadu, to Mumbai in the north.

These mountains, along with the biogeographically related Sri Lanka are considered a global biodiversity hotspot, noted especially for their high levels of endemism of reptiles, amphibians and plants. The Western Ghats are also species rich in mammals and birds, but are not comparably rich in endemics among these groups. However the mountains are considered as a bird endemic area, by Birdlife International.

The Western Ghats contain a variety of forest types, determined mostly by rainfall and elevation. The Western slopes of the ghats receive the bulk of the southwest monsoon rains, exceeding a copious 9000 mm (350 in) annually in some locations, and support luxuriant wet evergreen forests.

Moving east, as rainfall tends to decrease, forests are dominated by deciduous trees and thorny scrub species in the driest locations. Higher elevations, restricted to the southern ranges, support a wet-montane forest and grassland ecosystem, bringing its own unique diversity to this mosaic of forest types.

The sharp elevation and rainfall gradient, and the consequent variety of habitat types are provided as the main explanation for high local biodiversity in the mountain ranges of the Western Ghats.

Further, the discontinuous nature of the wet forests and drainage systems of the Western Ghats, are believed to have contributed to heightened levels of endemism among some taxa, by potentially facilitating local speciation and relictualism.

Natural areas of the Western Ghats of south India include a variety of forest types and topographic diversity. The gentle terrain and abundant grazing grounds that characterizes the lower hills of the Western Ghats, support large populations of Asian elephants and other large herbivorous mammals.

The large and varied prey-base also supports healthy populations of tigers, leopards, Indian wild dogs and a host of other smaller carnivorous mammals.

Some of the rarer mammals that occur in the drier forests include the slender Loris, striped hyena, fourhorned antelope, leopard cat and fishing cat. Birdlife is excellent, with over 250 species occurring in many of these locations. The rare white-bellied minivet and the Malabar lark, a Western Ghats endemic, are often best seen in these drier habitats.

Moist deciduous and evergreen are usually located at higher altitudes and the wetmontane ecosystem is restricted to altitudes above 1750msl. While they continue to support large mammals, the species community in the wet forests is better known for their cryptic, smaller and unique species assemblages.

Among the rarer and/or endemic mammals, the endangered and endemic primate, lion-tailed macaque is found here, along with brown mongoose, brown palm civet, Nilgiri marten, Salim Ali's fruit bat, Malabar spiny dormouse and Nilgiri tahr.

Birdlife can be spectacular, especially in the transition zone between moist deciduous and evergreen forests. A majority of the Western Ghats's nineteen endemic birds are found in these wetter habitats, as well as several of the sub-continental endemics.

These wet forests contain an excellent diversity of reptiles and amphibians at very high levels of endemism. Snakes are especially well represented among uropeltids and colubrids, while containing a good diversity of elepaids and viperids as well.

Lizards are well represented among agamids, geckonids and scincids. A species of endemic flying lizard (Draco) can be easily sighted displaying its bright yellow dewlap or gliding between trees in these wet forests and surrounding plantations.

The threatened Travancore tortoise and Cochin cane turtle are endemic to the wet forests of the Western Ghats. Close to 80 of about 120 species of amphibians are endemic to the Western Ghats, many of which are restricted to moist habitats.

Amphibians are generally inadequately explored in the Western Ghats, with new discoveries and taxonomic revisions adding to an ever increasing list of species, genera and even families. Plants and fishes are the other well studied groups that are known to be highly diverse and rich in endemics from the moist habitats in the Western Ghats.

The impressive and unique biodiversity of the Western Ghats continue to be threatened due to human activity. In recent history, over the last two centuries or so, much of its natural areas have been converted for settlements, plantations, roads and reservoirs. Irresponsible tourism and unplanned development continue to add to the historical pressures on the Western Ghats biota.

As such, very little natural vegetation occurs outside the protected areas throughout these mountain ranges. This is especially significant for the unique biodiversity of the wet forests which have historically occurred as a discontinuous narrow strip limited by altitude and rainfall. Further fragmentation of these wet habitats due to human activity has inevitably exposed the Western Ghats biota to the extinction vulnerabilities of small, isolated populations.

Fortunately, well planned protected area systems exist and in some places (the Nilgiri Biosphere Reserve) encompass extensive areas across management regimes thus providing umbrella protection for the Western Ghats biodiversity. The Western Ghats forests assume further significance by 'sponging' the seasonal monsoon rains to support the agricultural economy of the peninsular plains.

The natural beauty of the ghats cannot be overstated, with sheer cliffs, rolling grasslands, stunning mountain scenery, lush forests and river valleys sprinkled throughout the landscape of these mountains.

Several mountain peaks and rivers that originate in these mountains are of spiritual significance to local tribal people as well as people from afar. As such, the Western Ghats not only encompasses tremendous and globally significant biodiversity, but also influences the socio-economics and culture of peninsular India.