[2] Comprising an area of 265.72 square kilometres (102.6 sq mi), Nedumkayam reserve forest is administered as part of Karimpuzha Wildlife Sanctuary of Kerala in South India.

Nedumkayam is continuous with Silent Valley National Park, and also forms a part of the Nilgiri Biosphere Reserve.

As of 2004, there were populations of 10 IBA trigger species ranging from critically endangered/vulnerable to least concern according to IUCN categorisation and from A1 to A3 according to IBA categorization, namely: the lesser adjutant (Leptoptilos javanicus), white-rumped vulture (Gyps bengalensis), Nilgiri wood-pigeon (Columba elphinstonii), Malabar parakeet (Psittacula columboides), Malabar grey-hornbill (Ocyceros griseus), white-bellied treepie (Dendrocitta leucogastra), grey-headed bulbul (Pycnonotus priocephalus), rufous babbler (Turdoides subrufus), white-bellied blue-flycatcher (Cyornis pallipes), and crimson-backed sunbird (Nectarinia minima).

Maximum species richness was obtained during November and the highest diversity index was recorded during April.

[1] As of 2000, Nedumkayam is home to almost all mammal species found in the broader region of the Western Ghats: a total of 25 mammals, including the endemic and threatened lion-tailed macaque (Macaca silenus) and Nilgiri tahr (Hemitragus hylocrius).