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Location India, Assam
Central coordinates 92o 34.53' East  26o 55.18' North
IBA criteria A1
Area 22,000 ha
Altitude 100 - 300m
Year of IBA assessment 2004

Bombay Natural History Society

Site description Sonai-Rupai was declared as a Game Reserve in 1934, because of its rich biodiversity that included the Indian One-horned Rhinoceros Rhinoceros unicornis, and reported populations of Wild Buffalo Bubalus arnee (= bubalis). Both these species are, however, locally extinct from this sanctuary. Located about 40 km northwest of Tezpur town, in the district of Sonitpur, in northern Assam, Sonai-Rupai has a number of threatened birds that got little attention earlier. These are the White-winged Duck Cairina scutulata, Bengal Florican Houbaropsis bengalensis, Swamp Francolin Francolinus gularis and the occasional Rufous-necked Hornbill Aceros nipalensis (Choudhury 2000, 2002). This sanctuary is on the interstate border with Arunachal Pradesh. Sonai-Rupai was earlier part of Charduar Reserve Forest. The rivers Gabharu, Gelgeli, Sonai and Rupai flow through the Sanctuary. An added advantage is the presence of Doimara RF and beyond this the Eaglenest Wildlife Sanctuary across the border in Arunachal Pradesh, covering about 50,000 ha. For many species of fauna, it is one large wilderness area. The terrain in Sonai-Rupai is flat and gently sloping towards the south, typical of bhabar and terai areas. Towards north, promontories of the small hills of Arunachal Himalaya can be seen. Most of Sonai-Rupai is tree forest, but there are large patches of grassland.

Key Biodiversity 

AVIFAUNA: Preliminary surveys reveal about 160 species of birds, but detailed studies could yield more than 250 (A. U. Choudhury pers. comm. 2002). During the late 1980s, Rahmani et al. (1990) did surveys in search of the Bengal Florican. They could not sight the Bengal Florican, but found that nearly 200 ha of the Gelgeli grassland is one of the best grasslands of its kind and quite suitable for the florican. The vegetation compares well with other ideal florican habitats in Manas, Orang and Kaziranga. Choudhury (2002) also could not find the Bengal Florican either, but says “perhaps a few birds remain’’. However its presence was confirmed recently in this IBA (A. U. Choudhury pers. comm. 2004). As the forest of Sonai-Rupai is continuous with Doimara Reserve Forest and then Eaglenest Wildlife Sanctuary in Arunachal Pradesh, the bird life is extremely rich. Rufous-necked Hornbill Aceros nipalensis can be seen, along with forest species such as Grey Peacock Pheasant Polyplectron bicalcaratum, Himalayan Flameblack Dinopium shorii, Slaty Blue Flycatcher Ficedula tricolor, Maroon Oriole Oriolus traillii, Black-winged Cuckoo Shrike Coracina melaschistos, Small Niltava Niltava macgrigoriae, Black-backed Forktail Enicurus immaculatus, Slatybacked Forktail E. schistaceus, Sultan Tit Melanochlora sultanea, White-throated Bulbul Alophoixus flaveolus, Slaty-bellied Tesia Tesia olivea, Black-chinned Yuhina Yuhina nigrimenta, Lesser Necklaced Laughingthrush Garrulax moniliger, Greater Necklaced Laughingthrush G. pectoralis, Rufous-necked Laughingthrush G. ruficollis, Black-throated Sunbird Aethopyga saturata and Streaked Spiderhunter Arachnothera magna. Detailed investigation on the bird life has not been done in this site, so we do not know much about the Restricted Range species. The site lies at the interface of the Indo-Gangetic Plains (Biome-12) and Indo-Chinese Tropical Moist Forest (Biome-9), and at the edge of Eastern Himalayas Endemic Bird Area (EBA-130: Stattersfield et al. 1998), so it is likely that many more species of conservation concern are found here. Presently, we have included this site only on the basis of presence of threatened species (A1) criteria.

OTHER KEY FAUNA: Sonai-Rupai Wildlife Sanctuary has all the major mammal fauna present in Evergreen, Semi-evergreen and Moist Deciduous forests of Assam. Its continuity with the extensive forests of Arunachal Pradesh has enhanced its mammalian and avian diversity. It harbours the big four, i.e. Asian Elephant Elephas maximus, Tiger Panthera tigris, Leopard P. pardus, and Gaur Bos frontalis. Only One-horned Rhinoceros and Wild Buffalo are missing. Among primates it has Assamese Macaque Macaca assamensis and Rhesus Macaque M. mulatta. The smaller carnivores are Jungle Cat Felis chaus, Leopard Cat Prionailurus bengalensis, Golden Jackal Canis aureus, Large Indian Civet Viverra zibetha and Small Indian Civet Viverricula indica. Sambar Cervus unicolor, Hog Deer Axis porcinus and Barking Deer Muntiacus muntjak are found in this IBA.

The reptiles and amphibians found in Sonai-Rupai are not well recorded.

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 
White-winged Duck Asarcornis scutulata resident  2004  present  A1  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

2013 very high near favourable medium
Medium - based upon reliable but incomplete / partially representative data

Human intrusions and disturbance war, civil unrest and military exercises happening now majority/most of area/population (50-90%) very rapid to severe deterioration very high
Residential and commercial development housing and urban areas happening now majority/most of area/population (50-90%) very rapid to severe deterioration very high

Forest   0 0 moderate (70-90%) good (> 90%) near favourable

Whole area of site (>90%) covered by appropriate conservation designation  A comprehensive and appropriate management plan exists that aims to maintain or improve the populations of qualifying bird species  Unknown  medium 

Protected areas

Protected area Designation Area (ha) Relationship with IBA Overlap with IBA (ha)  
Sonai-Rupai Sanctuary 22,000 is identical to site 22,000  


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

Land use

Land-use Extent (% of site)
forestry -
Notes: Forest
nature conservation and research -
Notes: Riverine wetland
rangeland/pastureland -
Notes: Grassland

Acknowledgements Key contributors: Anwaruddin Choudhury, Goutam Narayan and Asad R. Rahmani.


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

Choudhury, A. U. (2002) Conservation of the White-winged Wood Duck Cairina scutulata in India, pp. 52-64. In: Birds of Wetlands and grasslands: Proceedings of the Salim Ali Centenary Seminar on Conservation of avifauna of wetlands and grasslands. Eds: Rahmani, A.R. and Ugra, G. Bombay Natural History Society, Mumbai. Pp. x+228.

Rahmani, A. R., Narayan, G., Rosalind, L. and Sankaran, R. (1990) Status of the Bengal Florican in India. pp. 55-78. In: Status and Ecology of the Lesser and Bengal Floricans, with reports on Jerdon’s Courser and Mountain Quail. Final Report. Bombay Natural History Society, Bombay.

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.

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Recommended citation  BirdLife International (2016) Important Bird and Biodiversity Area factsheet: Sonai-Rupai Wildlife Sanctuary. Downloaded from on 22/10/2016

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