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Location India, Assam
Central coordinates 90o 55.65' East  26o 43.13' North
IBA criteria A1, A2
Area 50,000 ha
Year of IBA assessment 2004

Bombay Natural History Society

Site description The Manas National Park, a world heritage site, is located in western Assam on the international border with Bhutan. The most well known of the wildlife reserves of northeast India and second only to Kaziranga, it was earlier called the North Kamrup Wildlife Sanctuary. The river Manas with its distributaries, the Beki and Hakua, flows through the Park. Other smaller streams include Jongrong, Gyati and Garuchara. Known for its scenic beauty, Manas is also home to a number of globally threatened birds and mammals. The Park has now the only viable population of the Critically Endangered Pigmy Hog Sus salvanius. An added advantage to Manas is the presence of the 102,300 ha Royal Manas National Park across the border in Bhutan. For many species, it is a large contiguous wilderness area. The terrain in Manas is mostly flat, gently sloping plain typical of bhabar and terai. Towards the north, small hilly promontories of the Bhutan Himalaya can be seen. Approximately half of Manas is savanna grassland, while the rest is Moist Deciduous and Semievergreen forest. There are no large beels (waterbody), but small beels and pools occur in the southern areas. The three main types of vegetation are: i) Tropical Semi-evergreen forests in the northern part of sanctuary; ii) Tropical Moist Deciduous Forests (the most common type); and iii) extensive alluvial grasslands in the western part of the National Park, comprising many grass species, and a variety of tree and shrub species (e.g. Dillenia pentagyna, Phyllanthus emblica, Bombax ceiba, and species of Clerodendrum, Leea, Grewia, Premna and Mussaenda). There is also a considerable variety of aquatic flora along riverbanks and in the numerous pools (Jain and Sastry 1983). Drier deciduous forests represent early stages in succession and are replaced by Moist Deciduous forests away from watercourses, which, in turn, are succeeded by Tropical Semi-evergreen climax forest. Grasslands cover about 50% of the Sanctuary. Some 393 species of dicotyledons, including 197 trees, and 98 species of monocotyledons have been identified.

Key Biodiversity 

AVIFAUNA: Around 310 bird species have been reported from this IBA (Narayan et al. 1989, Ali et al. 1985). Several uncommon species, including the Greater Adjutant Leptoptilos dubius and Lesser Adjutant Leptoptilos javanicus and Spot-billed Pelican Pelecanus philippensis can be seen here. Manas has perhaps, the largest known population of the Bengal Florican Houbaropsis bengalensis where Narayan, (1992) estimated about 80 birds in 1989-90. It is an important area for most of the tall wet grassland species, such as Swamp Francolin Francolinus gularis, Marsh Babbler Pellorneum palustre, Slender-billed Babbler Turdoides longirostris, Jerdon’s Babbler Chrysomma altirostre, Bristled Grass-warbler Chaetornis striatus and many others. Hodgson’s Bushchat Saxicola insignis, another tall grassland species is present in Manas during winter. Manas is one of the few places where the Vulnerable Finn’s Baya Ploceus megarhynchus is found nesting. According to the biome classification of BirdLife International (undated), Manas mainly lies in the Indo-Gangetic Plains (Biome-12) where 13 species are considered as biome represented. Except for Collared Myna Acridotheres albocinctus that anyway is restricted to Manipur and a small portion of adjoining Assam, all the remaining 12 species are found in Manas. Presence of such a high percentage of biome-restricted birds proves the habitat is still intact and in pristine condition. Based on the excellent bird life and significant populations of some globally threatened species, Manas Tiger Reserve is considered as one of the Outstanding IBAs of India (BirdLife International 2003).

OTHER KEY FAUNA: Manas harbours some of the richest mammalian diversity in India.

More than 60 mammals have been identified, including 22 listed in the Wildlife (Protection) Act 1972 (Rahmani, et al. 1992). Only the most endangered are mentioned here. This Park is the only known site for the globally threatened Pygmy Hog Sus salvanius.

A captive breeding and reintroduction programme is on going (G. Narayan, pers. comm. 2001). Hispid Hare Caprolagus hispidus is another endangered species doing well in Manas. Its pellets indicate its presence in all suitable grasslands. Some of the pure population of Wild Buffalo Bubalus arnee (= bubalis) is found in Manas. In all other areas interbreeding with domestic buffalos is a major problem. To the west of Manas river, in Bhutan, Golden Langur Trachypithecus geei is found.

Manas is also known for its large herds of Asian Elephant Elephas maximus and Hog Deer Axis porcinus. Before the devastation brought about by insurgency, it was not uncommon to see congregations of up to 200 Hog Deer. In deeper jungle, Clouded Leopard Neofelis nebulosa is found, but difficult to see due to its nocturnal habit and shy nature. There is a small population of Swamp Deer Cervus duvaucelii. Earlier, their habitat was shared by the Indian Rhinoceros Rhinoceros unicornis but sadly poachers killed most of these animals. Tiger Panthera tigris is still present, although in smaller numbers.

Reptiles are among the lesser-known animals of Manas. In addition to the Yellow Monitor Lizard Varanus flavescens and the King Cobra Ophiophagus hannah, which belong to the endangered category, Manas also harbours a variety of turtles and terrapins.

The Assam Roof Turtle Kachuga sylhetensis was recently found (Sharma 1988), which is a range extension for this extremely rare species. Other rare turtles are the Eastern Hill Terrapin Melanochelys tricarinata and the Indian Sawback or Roofed Terrapin Kachuga tecta.

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 
Lesser Adjutant Leptoptilos javanicus resident  2004  present  A1  Vulnerable 
Spot-billed Pelican Pelecanus philippensis resident  2004  present  A1  Near Threatened 
Lesser Kestrel Falco naumanni passage  2004  present  A1  Least Concern 
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 
Bengal Florican Houbaropsis bengalensis resident  2004  present  A1  Critically Endangered 
Rufous-necked Hornbill Aceros nipalensis resident  2004  present  A1  Vulnerable 
Grey-crowned Prinia Prinia cinereocapilla resident  2004  present  A1  Vulnerable 
Bristled Grassbird Chaetornis striata resident  2004  present  A1  Vulnerable 
Marsh Babbler Pellorneum palustre resident  2004  present  A1, A2  Vulnerable 
Jerdon's Babbler Chrysomma altirostre resident  2004  present  A1  Vulnerable 
Slender-billed Babbler Turdoides longirostris resident  2004  present  A1  Vulnerable 
Black-breasted Parrotbill Paradoxornis flavirostris resident  2004  present  A1, A2  Vulnerable 
White-throated Bushchat Saxicola insignis winter  2004  present  A1  Vulnerable 
Yellow Weaver Ploceus megarhynchus 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%) moderate to rapid 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 majority/most of area/population (50-90%) moderate to rapid deterioration high
Biological resource use logging & wood harvesting - unintentional effects: subsistence/small scale happening now some of area/population (10-49%) slow but significant deterioration medium
Human intrusions and disturbance recreational activities happening now small area/few individuals (<10%) no or imperceptible deterioration low
Natural system modifications fire & fire suppression - increase in fire frequency/intensity happening now small area/few individuals (<10%) slow but significant deterioration low

Protected areas

Protected area Designation Area (ha) Relationship with IBA Overlap with IBA (ha)  
Manas National Park 50,000 is identical to site 50,000  
Manas Sanctuary 39,100 protected area contained by site 39,100  
Manas Wildlife Sanctuary World Heritage Site 51,900 protected area contained by site 39,100  


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

Land use

Land-use Extent (% of site)
nature conservation and research -
Notes: Nature Conservation
tourism/recreation -
Notes: Tourism

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

Further web sources of information 

Alliance for Zero Extinction (AZE) species/site profile. This site has been identified as an AZE due to it containing a Critically Endangered or Endangered species with a limited range.


Ali, S., Daniel, J. C. and Rahmani, A. R. (1985) Study of ecology of certain endangered species of wildlife and their habitats. The floricans. Annual Report 1, 1984-1985. Bombay Natural History Society, Bombay. Pp. 79-83.

BirdLife International (2003) Saving Asia’s Threatened Birds: A Guide for Government and Civil Society. BirdLife International, Cambridge, U.K.

BirdLife International (undated) Important Bird Areas (IBAs) in Asia: Project briefing book. BirdLife International, Cambridge, U.K., Unpublished.

Choudhury, A. U. (1989) S.O.S. Manas : The Sentinel, 7 May, Guwahati.

Jain, S. K. and Sastry, S. R. K. (1983) Botany of some tiger habitats in India. Botanical Survey of India, Department of Environment, Government of India.

Narayan, G. (1992) Ecology, distribution and conservation of the Bengal Florican Houbaropsis bengalensis (Gmelin) in India. Ph.D. thesis, University of Bombay.

Narayan, G., Sankaran, R., Rosalind, L and Rahmani, A.R. (1989) The Floricans Houbaropsis bengalensis and Sypheotides indica. Annual Report 1988-89. Bombay Natural History Society. 39pp.

Rahmani, A. R., Narayan, G. and Rosalind, L. (1992) Threat to India’s Manas Tiger Reserve. Tigerpaper 14 (2): 22-28.

Sharma, S. (1988) A new record of the Assam Roof Turtle Kachuga sylhetensis (Jerdoni) form the Manas Wildlife Santuary. J. Bombay Nat. Hist. Soc. 85: 623.

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Recommended citation  BirdLife International (2016) Important Bird and Biodiversity Area factsheet: Manas National Park. Downloaded from on 24/10/2016

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