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Location India, Assam
Central coordinates 95o 37.50' East  27o 24.00' North
IBA criteria A1, A2
Area 19,200 ha
Altitude 120 - 200m
Year of IBA assessment 2004

Bombay Natural History Society

Site description Upper Dihing (East) Complex includes four reserve forests, namely Upper Dihing (East Block) including the area leased to oil fields (13,168 ha), Kakojan (2,345 ha), Duarmara (653 ha) and Torani (2,040 ha) Reserve Forests. The Upper Dihing (East Block), Kakojan and Digboi Oil field areas are contiguous, while Torani and Duarmara are isolated areas some distance away. These forests are among the last remaining patches of Tropical Evergreen Forests of some significance in Assam. The area consists of slightly undulating plains. Dibru, the main river, flows through the Upper Dihing and Kakojan Reserve Forests. Many small perennial streams criss-cross the area, notably the Kharjan river. Small jungle pools and natural or artificial swampy areas are also present (Lahkar 2001). These forests are globally important, as a sizeable number of the Whitewinged Duck Cairina scutulata is found here (Choudhury 1996, 1998). There are also relatively recent reports of the Masked Finfoot Heliopais personata from this site (Choudhury 1997). There is also a past record of the Baikal Teal Anas formosa (Hooper 1958). The vegetation of the site is mainly Tropical Wet Evergreen Rain Forest type. The important tree species are Dipterocarpus macrocarpus, Shorea assamica, Mesua ferrea, Terminalia myriocarpa, Artocarpus chaplasha, Dillenia indica, Anthocephalus cadamba, Bombax ceiba and Ficus spp. Scattered marshy depressions bear Alpinia allughas, Arundo donax, Imperata cylindrical and Saccharum spp. Tectona grandis is seen on roadside plantations (Lahkar 2001).

Populations of IBA trigger species

Species Season Period Population estimate Quality of estimate IBA Criteria IUCN Category
White-winged Duck Asarcornis scutulata resident  2004  present  A1  Endangered 
Lesser Adjutant Leptoptilos javanicus resident  2004  present  A1  Vulnerable 
Greater Adjutant Leptoptilos dubius breeding  2004  present  A1  Endangered 
White-bellied Heron Ardea insignis resident  2004  present  A1  Critically Endangered 
White-rumped Vulture Gyps bengalensis non-breeding  2004  present  A1  Critically Endangered 
Greater Spotted Eagle Clanga clanga winter  2004  present  A1  Vulnerable 
Slender-billed Vulture Gyps tenuirostris non-breeding  2004  present  A1  Critically Endangered 
Masked Finfoot Heliopais personatus resident  2004  present  A1  Endangered 
Pale-capped Pigeon Columba punicea resident  2004  present  A1  Vulnerable 
Rufous-necked Hornbill Aceros nipalensis resident  2004  present  A1  Vulnerable 
Yellow-vented Warbler Phylloscopus cantator 2004  present  A2  Least Concern 
Snowy-throated Babbler Stachyris oglei resident  2004  present  A1, A2  Vulnerable 
Chestnut-backed Laughingthrush Garrulax nuchalis resident  2004  present  A2  Near Threatened 


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

Land use

Land-use Extent (% of site)
agriculture -
Notes: Agriculture
forestry -
Notes: Forest
urban/industrial/transport -
Notes: Industry (oil installations)

Acknowledgements Key contributor: Kulojyoti Lahkar.


Choudhury, A. U. (1996) Survey of the White-winged Wood Duck and the Bengal Florican in Tinsukia district and adjacent areas of Assam and Arunachal Pradesh. The Rhino Foundation for nature in NE India, Guwahati.

Choudhury, A. U. (1997) Current status of the Masked finfoot in India. Newsletter for Birdwatchers 37(5): 90-91.

Choudhury, A. U. (1998) Status and conservation of the white-winged duck in eastern Assam, India. OBC Bulletin 28:14-17.

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

Hooper, C. D. (1958) Occurrence of the Baikal Teal in Assam. J. Bombay Nat. Hist. Soc. 55 (2): 359-360.

Lahkar, K. (2001) Birds of Upper Dihing (East Block) and Kakojan Reserved Forests and Digboi Forest Area. Report to the Bombay Natural History Society, Mumbai. 30 Pp. Unpublished.

Lahkar, K. (2002) Notable bird records from Digboi. The Rhino Foundation for Nature in NE India Newsletter 4: 23.

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Recommended citation  BirdLife International (2014) Important Bird Areas factsheet: Upper Dihing (East) Complex. Downloaded from on 30/08/2014

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