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Location India, Assam
Central coordinates 94o 17.50' East  27o 33.50' North
IBA criteria A1, A2, A3
Area 18,000 ha
Altitude 100 - 1,000m
Year of IBA assessment 2004

Bombay Natural History Society

Site description This site includes two reserve forests, Subansiri in Dhemaji district and Dulung in Lakhimpur district in northeastern Assam. The river Subansiri passes through the middle of the IBA, while its tributaries Pavo, Geruka, Dirpai and Dulung drain other parts of the site. It is here that the Subansiri River debouches into the plains, forming a broad braided stretch of aquatic and terrestrial habitats. The terrain of the site is hilly, as it covers foothills of the Eastern Himalayas. Small flat areas occur along the southern portion. The higher parts of Subansiri Reserve Forest are more than 300 m above msl. The site is known for wildlife, especially Asian Elephant Elephas maximus and birds. There was an excellent patch of terai grassland in Dirpai area of Subansiri RF, where the Bengal Florican Houbaropsis bengalensis and the Swamp Francolin Francolinus gularis used to occur. While the call of the francolins is still heard, the florican has become sporadic. This is mainly due to encroachment and settlements in its grassland habitat. There is also a record of the Chestnut-breasted or Red-breasted Hill Partridge Arborophila mandellii from the higher areas of Subansiri RF (Choudhury 2000). The entire area is clothed with thick, lush Tropical Evergreen and Semi-evergreen forests, with absolute habitat contiguity with Taley Valley Wildlife Sanctuary (IBA) of Arunachal Pradesh, across the river Subansiri.

Key Biodiversity 

AVIFAUNA: Subansiri is an extremely important habitat for bird life. More than 200 bird species have been identified, some of them rare (A. U. Choudhury pers. comm. 2003). This site represents Biome-9 (Indo- Chinese Tropical Moist Forests) but birds of other biomes (5, 7, 8, 11 and 12) are also found here, some species only in winter. Some of the important species noted are the Himalayan Griffon Gyps himalayensis, Rufous-breasted Blue Flycatcher Ficedula hodgsonii, Slaty Flycatcher F. tricolor, Ferruginous Flycatcher Muscicapa ferruginea, Chestnut-headed Tesia Tesia castaneocoronata, Grey-bellied Tesia T. cyaniventer, Blue-throated Barbet Megalaima asiatica, Bay Woodpecker Blythipicus pyrrhotis, Maroon Oriole Oriolus traillii, Black-naped Oriole O. tenuirostris, Grey Treepie Dendrocitta formosae, Black-winged Cuckoo Shrike Coracina melaschistos, White-throated Bulbul Alophoixus flaveolus, Black Bulbul Hypsipetes leucocephalus, Grey-winged Blackbird Turdus boulboul, Redheaded Babbler Stachyris ruficeps, Himalayan Golden-backed Woodpecker Dinopium shorii, Necklaced Laughingthrush Garrulax moniligerus, Black-gorgeted Laughingthrush G. pectoralis and Rufous-necked Laughingthrush G. ruficollis.

OTHER KEY FAUNA: Subansiri Reserve Forest has most of the major mammal species found in Tropical Evergreen and Semi-evergreen forests of Assam.

It has four species of primates, such as the Slow Loris Nycticebus coucang, Capped Langur Trachypithecus pileatus, Assamese Macaque Macaca assamensis and Rhesus Macaque M. mulatta.

Asiatic Black Bear Ursus thibetanus is perhaps the largest predator but is confined to higher altitudes. In the steamy jungles and tall grasslands, there are Tiger Panthera tigris, Leopard P. pardus, Clouded Leopard Neofelis nebulosa and Marbled Cat Pardofelis marmorata (Choudhury 1996). Gaur Bos frontalis, Serow Nemorhaedus sumatraensis, Sambar Cervus unicolor, and Barking Deer Muntiacus muntjak are the ungulates. Malayan Giant Squirrel Ratufa bicolor is quite common in closed canopy forest. The Gangetic River Dolphin Plantanista gangetica is usually found in the monsoon, while Common Otter Lutra lutra, and Smooth Indian Otter Lutrogale perspicillata are found throughout the year in undisturbed streams and rivers.

Populations of IBA trigger species

Species Season Period Population estimate Quality of estimate IBA Criteria IUCN Category
Swamp Francolin Francolinus gularis resident  2004  present  A1  Vulnerable 
Chestnut-breasted Partridge Arborophila mandellii resident  2004  present  A1  Vulnerable 
White-winged Duck Asarcornis scutulata resident  2004  present  A1  Endangered 
Lesser Adjutant Leptoptilos javanicus resident  2004  present  A1  Vulnerable 
Pallas's Fish-eagle Haliaeetus leucoryphus resident  2004  present  A1  Vulnerable 
White-rumped Vulture Gyps bengalensis non-breeding  2004  present  A1  Critically Endangered 
Slender-billed Vulture Gyps tenuirostris non-breeding  2004  present  A1  Critically Endangered 
Bengal Florican Houbaropsis bengalensis resident  2004  present  A1  Critically Endangered 
Rufous-necked Hornbill Aceros nipalensis resident  2004  present  A1  Vulnerable 

IBA Monitoring

2003 high not assessed not assessed
Good - based on reliable and complete / representative data

Agriculture and aquaculture annual & perennial non-timber crops - small-holder farming happening now small area/few individuals (<10%) slow but significant deterioration low
Agriculture and aquaculture livestock farming and ranching (includes forest grazing) - small-holder grazing, ranching or farming happening now small area/few individuals (<10%) slow but significant deterioration low
Biological resource use hunting & collecting terrestrial animals - intentional use (species being assessed is the target) happening now small area/few individuals (<10%) slow but significant deterioration low
Biological resource use logging & wood harvesting - unintentional effects: subsistence/small scale happening now small area/few individuals (<10%) slow but significant deterioration low
Natural system modifications dams & water management/use - large dams happening now some of area/population (10-49%) very rapid to severe deterioration high


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

Land use

Land-use Extent (% of site)
forestry -
Notes: Forest

Acknowledgements Key contributors: Anwaruddin Choudhury, Neeraj Vagholikar, Manju Menon and Bikul Goswami.


Choudhury, A. U. (1996) The marbled cat Felis marmorata Martin in Assam- some recent records. J. Bombay Nat. Hist. Soc. 93(3): 583- 584.

Choudhury, A. U. (2000) The Birds of Assam, Gibbon Books & WWFIndia NE Region, Guwahati. Pp. 240.

Choudhury, A. U. (2002) Comments on the Environmental Impact Assessment (EIA) of Kameng and Lower Subansiri Hydroelectric Projects, Arunachal Pradesh and Assam. Pp. 8. + maps.

Saghal, B. and Sharma, S. C. (2002) Lower Subansiri Site Visit. Report submitted to Government of India, New Delhi. Pp. 22.

Vagholikar, N. and Ahmed, M. F. (2003) Tracking a hydel project - the story of Lower Subansiri. The Ecologist Asia 11(1): 25-32.

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Recommended citation  BirdLife International (2016) Important Bird and Biodiversity Area factsheet: Subansiri. Downloaded from on 25/10/2016

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