The Silent Valley National Park is a unique preserve of natural rainforests. The Valley beckons us to witness the marvelous life that expresses itself in an incredible chaos of plants, animals, birds and insects. The most famous resident of the Park is Lion Tailed Macaque whose name has become almost synonymous with that of the Valley
40 Kms north east of Mannarkad, spread over 90 sq. kms is Silent Valley, a virgin forest, which is believed to be the role surviving bit of evergreen forests in the Sahya Ranges or Western Ghats. It is very much interesting for everyone to know about Silent Valley. The Silent Valley has got its name because it is devoid even of the chirping of cicadas. The Silent Valley National Park is one of the most magnificent gifts of nature to mankind.
Geographically, the Silent Valley and the adjacent forests of the Western Ghats represent the ecological islands. The biodiversity of Silent Valley is an isolated one. It is due to the physical barriers of the Palakkad gap. This isolation is actually the preserving factor of the flora and fauna in Silent Valley. The valley is shielded from the extreme climates as well as anthropogenic interventions and so it remains as an ecological island with a special climatic conditions.
Silent Valley is a rich biodiversity with more than 1000 species of flowering plants which include about 110 species of orchids, more than 34 species of mammals, about 200 species of butterflies, 400 species of moths, 128 species of beetles of which 10 are new to science, about 150 species of birds including almost all the 16 endemic birds of southern India. New species of orchids found here are Oberonia bisaccata, Liparis indiraii, Eriatiagii and Ipsea malabarica. Scutellaria oblonga and Anodendron rhinos porum, two Sri Lankan plants have also been recorded.
The River Kunthi originates from the Nilgiri hills, from an altitude of 2000 m above sea level, and travels through the entire Silent Valley and rushes down to the plains through the deep forest. The River Kunthi never turns brown and is always crystal clear. Many forms of fresh water life is in Kuthi river - 12 species of fish have been identified out of which two are new to science. 19 species of frogs including 2 new species have been sighted from the valley.