Silent Valley National Park, Kerala

Silent Valley National Park is a national park in Kerala. It is situated in the Nilgiri hills and encompasses a core area of 89.52 km2 and a buffer zone of 148 km2. This national park contains uncommon plant and animal species. This region was explored by botanist Robert Wight in 1847. It is situated on the boundary between the Mannarkkad Taluk of Palakkad district, the Nilambur Taluk of Malappuram district in Kerala, and the Nilgiris district of Tamil Nadu.

Silent Valley National Park is a stunning example of Kerala’s only remnant rainforest. It is a historical example of the movement to safeguard the forest. In 1984, Silent Valley has designated a national park, and it was formally launched in 1985. Initially, the area under the Division that comprises the core zone of the national park was only 89.52 square kilometers. As a buffer zone, 148 square kilometers were added to this Division in 2007. The woodlands of Silent Valley were designated Reserved Forest in 1914.

Silent Valley National Park was a part of the South Malabar Forest Division with its headquarters in Nilambur till 1921. It was under the jurisdiction of the Palakkad Forest Division from 1921 until 1988.

History of the Silent Valley National Park

In 1847, the watersheds of the Silent Valley region were first explored and investigated. In 1914, the forest of the Silent Valley National Park region was designated as a reserved forest. From 1927 to 1976, certain portions of the Silent Valley forest area were subject to forestry operations. In 1928-29, it was determined that Sairandhri on Kunthipuzha was an ideal location for power generation.

In 1958, an inventory and investigation were conducted, and the Kerala State Electricity Board proposed a hydroelectric power project of 120 MW and INR 17 crores. The national committee on environmental planning and coordination (NCEPC) analyzed the proposal for the hydroelectric project and proposed 17 precautions in the event that the project cannot be abandoned. The Kerala Forest Research Institute conducted an environmental impact study in the Silent Valley region in 1977 and proposed that the region be designated a biosphere reserve. In 1978, the Indian prime minister approved the project with the stipulation that the state government enacts the necessary safeguarding legislation.

IUCN (Ashkhabad, USSR, 1978) adopted a resolution recommending the protection of lion-tailed macaques in the Silent Valley and Palakkad regions. The Keralan government passed the Silent Valley protection area (protection of ecological balance) act in 1979. 1979. An eminent ornithologist, Dr. Salim Ali, visited the valley and urged the abandonment of the hydroelectric project. The Kerala Sasthra Sahithya Parishath has released a socio-political and techno-economic assessment of the Silent Valley hydroelectric project.

A writ petition was filed with the Kerala High Court against the clear felling of forests in the hydroelectric project area, and the Court ordered the clear felling to cease. Dr. M.S. Swaminathan, a renowned agricultural scientist, visited the Silent Valley region and proposed establishing a national rain forest Biosphere reserve in Silent Valley and the surrounding forests.

In January 1980, the Kerala High Court lifted the stay on clear felling. In 1980, the then-Honorable Smt. Indira Gandhi served as the prime minister of India. The Indian Prime Minister requested that further construction in the project area be halted until all aspects have been thoroughly discussed. The government of Kerala designated the Silent Valley region, excluding the hydroelectric project area, as a national park in December 1980.

Prof. M.G.K. Menon will lead a multidisciplinary committee to determine whether the hydroelectric project can be implemented without causing significant ecological damage. Prof. Menon’s committee submitted its report at the beginning of 1983. Following a thorough examination of the Menon report, the then-Indian prime minister decided to abandon the hydroelectric project.

The Silent Valley woodlands were designated a national park on November 15, 1984. On September 7, 1985, the Silent Valley national park was formally inaugurated by the then-Prime Minister of India, Shri. Rajiv Gandhi. The Silent Valley National Park was incorporated into the core area of the Nilgiri Biosphere Reserve on September 1, 1986. On June 11, 2007, a 148-square-kilometer buffer zone was added to Silent Valley National Park. Sri. V S Achuthananthan, the Chief Minister of Kerala, dedicated the Buffer Zone to the nation on September 23, 2007.

Geography of Silent Valley National Park

Silent Valley National Park is located in the southwest part of the Nilgiris mountain range. The entirety of the Silent Valley National Park is a roughly rectangular, enclosed plateau. It features steep, continuous ridges along its eastern, northern, and northeastern boundaries, and a slightly lower ridge along its western and southern borders. The entire length of the plateau dips towards the bed of Kunthipuzha, which divides it in two. The terrain is mainly undulating, with steep cliffs and several hills. The elevation spans from 900 to 2,300 meters above mean sea level, with the highest peak reaching 2,382 meters (Anginda peak).

The terrain is mainly undulating, with steep cliffs and several hills. The elevation spans from 900 to 2,300 meters above mean sea level, with the highest peak reaching 2,382 meters (Anginda peak). The area lies entirely on a plateau to the north of Mannarkkad, which is formed by the outer slopes of the hills. These forests cover the major basin of the Kunthipuzha, which flows from north to south and drains into the Bharathapuzha.

A perennial river named Kunthipuzha flows from north to south across the western portion of the Silent Valley National Park, eventually merging with Bharathapuzha. Kunthancholapuzha, Karingthodu, Madrimaranthode, Valiaparathodu, and Kummathanthode are this river’s major tributaries. All major tributaries of Kunthipuzha begin on the eastern side of the Valley’s upper slopes. During the summer, the streams on the western slopes are dry.

The Bhavani River is a tributary of one of India’s greatest rivers, the Cauvery. The river originates in Nilgiris and drains the Nilgiri Hills’ southern slope. After flowing south for a few kilometers, the river enters Kerala through a deep gorge and then continues south for another twenty kilometers between two high, forested ridges till it reaches Mukkali. At Mukkali, Bhavani makes a sharp swing of 120 degrees to the northeast and runs for a further 25 kilometers through the Attappady plateau and 7 kilometers along the interstate boundary.

The climate of Silent Valley National Park

Due to changes in elevation from the plains to the Ghats, where the hills are drier and cooler and the lowlands are humid and hot, there are significant differences in climate. From April to September, the prevailing winds are from the west and southwest, whereas from October to March, they are from the east. In April and May, there are infrequent thunderstorms. Both the southwest and northeast monsoons bring precipitation to this region. The southwest monsoon, which begins in the first week of June, accounts for the majority of the precipitation. The heaviest precipitation occurs in June, July, and August.

The variance in rainfall intensity is evident throughout the region. From the foothills to the high mountains, there is an increase in precipitation. The elevated hills on the western side of Silent Valley receive an average of 5045 mm of precipitation, as measured at Arthala at 1200 m elevation, followed by Neelikkal at 1005 m elevation, which receives 4364 mm of precipitation. At higher heights, rainfall around Walakkad can reach up to 6,500 millimeters. The average minimum temperature fluctuates between 8 and 14 degrees Celsius, while the average maximum temperature ranges between 23 and 29 degrees Celsius.

Flora and Fauna of Silent Valley

The Silent Valley National Park’s valley areas are located in an Ecoregion of tropical and subtropical moist broadleaf forests. In the region of the South Western Ghats montane rain forests, there are hilly regions above 1,000 meters. Above 1,500 meters, the evergreen forests give way to stunted forests, called sholas, interspersed with open grassland, both of which are of interest to ecologists because the region’s rich biodiversity has never been affected by human settlements. Several endangered species are endemic to this region. Here, new plant and animal species are frequently discovered.

Flora of Silent Valley National Park

The Silent Valley National Park’s flora consists of over 1000 species of flowering plants, 108 species of orchids, 100 ferns and fern allies, 200 liverworts, 75 lichens, and approximately 200 species of algae. The majority of these plants are the Western Ghats endemic. 966 species belonging to 134 families and 599 genera make up the currently recognized Angiosperm flora. There are 701 Dicotyledons, which are organized into 113 families and 420 genera. There are 265 species of Monocotyledons in this region, spread across 21 families and 139 genera.

Orchids with 108 species, including the rare, endemic, and critically endangered orchids Ipsea malabarica, Bulbophyllum silentvalliensis, and Eria tiagii, Grasses (56), Legumes (55), Rubiaceae (49), and Asters (45). There are numerous uncommon, endemic, and economically valuable species, such as cardamom Ellettaria cardamomum, black pepper Piper nigrum, yams Dioscorea spp., beans Phaseolus spp., a pest-resistant breed of rice Oryza Pittambi, and 110 plant species essential to Ayurvedic medicine. Seven new plant species have been discovered in Silent Valley, including the Balsaminaceae species Impatiens sivarajanii in 1996.

Fauna of Silent Valley


In Silent Valley National Park, the Zoological Survey of India researched and cataloged over 315 species of diverse faunal groups, including Annelida, Arthropoda (Insecta), Mollusca, Fishes, Amphibia, Reptilia, and Mammals. There were eight new records for India and thirty-seven for the Western Ghats. The Western Ghats are home to 39 endemic species, including 15 invertebrates, out of 315 total species.


Approximately 41 animals are documented in the region. The region is home to several creatures, including primates. Due to the area’s unique vegetation and geography, a number of arboreal animals call it home. In this region, you can see Elephants, Lion Tailed Macaques, Nilgiri Langurs, Nilgiri Tahrs, Tigers, Leopards, Sloth bears, Gaur, etc.

The populations of the Lion Tailed Macaque (Macaca silenus) are restricted to tropical moist evergreen woods. The majority of LTM observations are made in the park’s southern part and neighboring Cullenia-Palaquium tree association regions. They prefer altitudes between 700 and 1600 meters.

Nilgiri Marten (Martes gwatkinsi) and Rusty-spotted cat (Felis rubiginosa) are among the eight smaller carnivores documented in Silent Valley and adjacent forest areas of Nilgiri Biosphere Reserve.


Silent Valley National Park is home to a total of 211 species of birds belonging to 40 families and 15 orders. Twenty-five of the thirty species is uncommon in the region. Studies of damaged ecosystems reveal the highest bird diversity in the area. The pristine evergreen forest is teeming with endemic species. It is the habitat of the elusive Malay/Tiger Bittern. There are approximately 20 species of raptors here. Passeriformes are the most abundant in the region, with 113 species belonging to 17 groups.


Snakes and other reptiles have one of the greatest conceivable ranges in Silent Valley. It has been verified that 25 species of snakes exist. There is evidence of at least 19 other occurrences in the region. It is home to the largest venomous snake, the King Cobra (Ophiophagus Hannah), as well as rare species such as the Beddome’s keelback (Amphiesma beddomei) and the Ceylon cat snake (Boiga ceylonensis). The most commonly encountered snake is the Rat snake (Ptyas mucosus).

There are also small terrestrial and burrowing species such as Kukri snakes (Oligodon spp), the shield tail snake (Uropeltidae), and Keel backs (Amphiesma, Macropisthodon, and Xenochropis spp). In addition, rare species such as the Travancore tortoise (Indotestudo travancorica) and the Horsfield’s spiny lizard (Salea horsfieldii) are also present.


In the region, 47 species of amphibians were documented, including some endemics. Bufo quiet valleynsis, Raorchestes lechiya, Micrixalus nudis, M. thampii, Nannobatrachus beddomei, Pedostobes tuberculosus, Philalithus signatus, Ramanella triangulata, Rhacophorus malabaricus, etc. are among them.


Twelve fish species have been documented in the Kunthi River. Approximately 40 species of fish have been documented in the combined Kuthi and Bhavani River basins. Anguilla bengalensis, Barillius gatensis, Channa gachua, Garra mullya, G. menoni, Glyphothorax gnnadalei, Homaloptera montana, H. pillaii, Lepiodocephalus thermalis, Noemacheilus triangularis, N. guentheri, and Puntius melanax are some of the species found in the


A total of 164 species of butterflies have been documented in the region. Sahyadri Birdwing, Pachliopta pandiyana, Papilio liomedo, Papilio Buddha, Parantirrhoea marshalli, Travancore Evening Brown, and Burara gomata kanara are examples of rare butterflies. Also present are 400 species of moths belonging to 19 families. The majority of butterflies belonging to the Nymphalidae, Papilionidae, and Pieridae families.

There were some indigenous and unusual species in the fauna. According to reports, 18 species of butterflies are extremely rare. The majority of the documented moths belong to the Noctuidae, Pyralidae, Geometridae, and Arctiidae families. In general, the Lepidopteran fauna exhibited affinities with Sri Lankan, Malayan, and Australian species. In addition to these 35 species of Odonates, 69 species of ants have been documented in Silent Valley.

Ecological Importance of Silent Valley National Park

The Western Ghats include one of the world’s most diverse and unknown ecosystems. The forests of Silent Valley National Park are among the purest, most distinctive, and most prolific in the world. In a biogeographical sense, Silent Valley National Park and the surrounding woodlands are ‘Ecological islands’ where circumstances that existed before the onset of human activity still exist. Here, the species diversity and endemism of evergreen and semi-evergreen communities are exceptional.

There are 41 species of mammals, 211 species of birds, 49 species of reptiles, 47 species of amphibians, 12 species of fish, 164 species of butterflies, and 400 species of moths here. In addition, the park is home to a viable population of Lion-tailed macaques, who are also the Park’s flagship species. Irulas, Kurumbas, Mudugas, and Kattunaikkars are among the indigenous tribal tribes that reside inside the Silent Valley National Park’s boundaries; the cultural history of these people is highly safeguarded. 

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