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Location India, Kerala
Central coordinates 76o 25.78' East  11o 7.90' North
IBA criteria A1, A2, A3
Area 8,952 ha
Altitude 658 - 2,383m
Year of IBA assessment 2004

Bombay Natural History Society

Site description Silent Valley is a rectangular tableland enclosed by a high contiguous ridge along its northern and eastern borders, and by a lower, irregular ridge along its western and southern borders. It is flanked by steep escarpments to the south and west, which descend some 1,000 m to the plains of Kerala, and by sheer cliffs to the north and east which rise a further 1,000 m to the Upper Nilgiri Plateau. Kunthipuzha river flows southwards through the entire 15 km length of the Park, dividing it into a narrow western sector of less than 2 km and a wider eastern sector of 5 km. The valley is drained by five main tributaries of the Kunthipuzha, which originate near the eastern border and flow westwards. Only a few minor streams drain into the Kunthipuzha from the western sector. The river is uniformly shallow, with no floodplains. Its bed falls from 1,861 m to 900 m over a distance of 12 km, the last 8 km being particularly level, with a fall of only 60 m. Kunthipuzha is one of the less torrential rivers of the Western Ghats, with a pesticide-free catchment area. The soil is blackish and slightly acidic in the evergreen forests, where there is good accumulation of organic matter. The underlying rock in the area is granite with schists and gneiss, which give rise to the loamy laterite soils on slopes (Anon., undated, 1981, 1982; Unnikrishnan, 1989). The total area is 8,951.65 ha. The Park is contiguous to the proposed Karimpuzha National Park (22,500 ha) in the north and to Mukurthi National Park (7,846 ha), Tamil Nadu, in the northeast. The altitude ranges from 658 m to 2,383 m (Balakrishnan 1984). Most of the Park lies between 880 m and 1,200 m (Anon. undated). High peaks such as Anginda (2,383 m), Sispara (2,206 m) and Kozhipara (1,904 m) occur in the northern part of the Park. Four main types of vegetation can be recognized: Tropical Evergreen Forest, Subtropical Hill Forest, Shola forest and grasslands which are restricted to the narrow sector west of the Kunthipuzha and to the higher slopes and hill tops in the eastern sector. Seven new plant species have been recorded from the Silent Valley (Manilal 1988), as well as many rare, endemic and economically valuable species, such as Cardamom Elettaria cardamomum, Pepper Piper nigrum, Yam Dioscorea spp., various beans Phaseolus spp., a pest-resistant strain of Rice (species unknown), and 110 plant species of importance in Ayurvedic medicine (Nair et al. 1980).

Populations of IBA trigger species

Species Season Period Population estimate Quality of estimate IBA Criteria IUCN Category
Nilgiri Woodpigeon Columba elphinstonii resident  2004  present  A1, A2, A3  Vulnerable 
Malabar Parakeet Psittacula columboides 2004  present  A2, A3  Least Concern 
Malabar Grey Hornbill Ocyceros griseus 2004  present  A2, A3  Least Concern 
White-bellied Treepie Dendrocitta leucogastra 2004  present  A2, A3  Least Concern 
Grey-headed Bulbul Pycnonotus priocephalus 2004  present  A2, A3  Near Threatened 
Broad-tailed Grassbird Schoenicola platyurus resident  2004  present  A1, A2  Vulnerable 
Rufous Babbler Turdoides subrufa 2004  present  A2, A3  Least Concern 
Wynaad Laughingthrush Garrulax delesserti 2004  present  A2, A3  Least Concern 
Black-chinned Laughingthrush Strophocincla cachinnans resident  2004  present  A1, A2, A3  Endangered 
Black-chinned Laughingthrush Strophocincla cachinnans resident  2004  present  A2, A3  Endangered 
Nilgiri Blue Robin Myiomela major resident  2004  present  A1, A2, A3  Endangered 
Black-and-rufous Flycatcher Ficedula nigrorufa resident  2004  present  A2, A3  Near Threatened 
Nilgiri Flycatcher Eumyias albicaudatus resident  2004  present  A2, A3  Near Threatened 
White-bellied Blue-flycatcher Cyornis pallipes 2004  present  A2, A3  Least Concern 
Crimson-backed Sunbird Nectarinia minima 2004  present  A2, A3  Least Concern 
Nilgiri Pipit Anthus nilghiriensis resident  2004  present  A2, A3  Vulnerable 

Protected areas

Protected area Designation Area (ha) Relationship with IBA Overlap with IBA (ha)  
Silent Valley National Park 8,952 is identical to site 8,952  


IUCN habitat Habitat detail Extent (% of site)
Forest   -
Grassland   -

Land use

Land-use Extent (% of site)
forestry -
Notes: Forestry
nature conservation and research -
Notes: Nature conservation and research

Acknowledgements Key contributor: The IBA Team.


Anonymous (1981) Flora and fauna of Silent Valley, Attappadi and Sabarigiri forests. Report of the Study Team appointed by the Government of Kerala. Kerala State Electricity Board, Trivandrum. Pp. 108.

Anonymous (1982) Ecological aspects of the Silent Valley. Report of the Joint Committee, Department of the Environment, Government of India, New Delhi. Pp. 44.

Anonymous (undated) Report of the Task Force for the ecological planning of the Western Ghats. National Committee on Environmental Planning and Coordination. Government of India, New Delhi. Pp 20.

Balakrishnan, M. (1984) The larger mammals and their endangered habitats in the Silent Valley forests of South India. Biological Conservation 29: 277-286.

Basheer, A. C. A. and Nameer, P. O. (1990) Some observations on the Birds of Silent Valley National Park. In: Bird conservation-strategies for the Nineties & Beyond (eds. Verghese, A., Sridhar, S., & Chakravarthy, A.K.), Ornithological Society of India, 1993. Pp. 131-136.

BirdLife International (2001) Threatened Birds of Asia: The BirdLife International Red Data Book. BirdLife International, Cambridge, U.K.

Jayson, E. A. (1990) Community ecology of birds in Silent Valley. In: Ecological studies and long-term monitoring of biological processes in Silent Valley National Park. Kerala Forest Research Institute Research Report. Pp. 55-107.

Kerala Forest Dept (1990) Silent Valley National Park. Nomination dossier for World Heritage List. Kerala Forest Department, Trivandrum. Pp. 66.

Manilal, K. S. (1988) Flora of Silent Valley tropical rainforests of India. The Mathrubhumi (MM) Press, Calicut. Pp. 398.

Mathew, G. (1990) Studies on the lepidopteran fauna of Silent Valley. In: Ecological studies and long-term monitoring of biological processes in Silent Valley National Park. Kerala Forest Research Institute Research Report. Pp. 13-53.

Nair, V. C., Vajravelu, E., Bhargavan, P. (1980) Preliminary report on the botany of Silent Valley (Palghat District, Kerala). Botanical Survey of India, Coimbatore.

Santharam, V. (1996) A note on the endemic Broad-tailed Grass Warbler. J. Bombay Nat. Hist. Soc. 93: 587.

Stattersfield, A. J., Crosby, M. J., Long, A. J. and Wege, D. C. (1998) Endemic Bird Areas of the World: Priorities for Biodiversity Conservation. BirdLife Conservation Series No. 7. BirdLife International, Cambridge, U.K.

Unnikrishnan, P. N. (1989) Silent Valley National Park Management Plan 1990.91-99.2000. Silent Valley National Park Division, Mannarghat. Pp 83.

Vijayan, L., Prasad, S. N., Balasubramanian, P., Gokula, V., Ramachandran, N. K., Stephen, D., and Mahajan, M. V. (1999) Impact of human interference on the plant and bird communities in the Nilgiri Biosphere Reserve. Project Report. Salim Ali Centre for Ornithology and Natural History, Coimbatore.

Zacharias, V. J. and Gaston, A. J. (1999) The recent distribution of endemic, disjunct and globally uncommon birds in the forests of Kerala State, south-west India. Bird Conservation International. 9:191–225.

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Recommended citation  BirdLife International (2014) Important Bird Areas factsheet: Silent Valley National Park. Downloaded from on 02/09/2014

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