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Location India, Andaman and Nicobar
Central coordinates 93o 31.00' East  8o 12.00' North
IBA criteria A1, A2
Area 1,683 ha
Altitude 0 - 323m
Year of IBA assessment 2004

Bombay Natural History Society

Site description The Nicobar Islands can be divided into three distinct subgroups: the Great Nicobar subgroup, the Nancowry subgroup and the Car Nicobar subgroup. Tillanchong, Camorta, Katchal, Nancowry and Trinkat Islands lie in the Nancowry subgroup of islands, c. 58 km north of the Great Nicobar subgroup. This subgroup consists of 10 islands and smaller islets of which one island and two islets are uninhabited (Sankaran 1998). Of these, three islands are larger than 100 sq. km, two are 36 and 67 sq. km and three are less than 17 sq. km. Tillanchong is uninhabited and a wildlife Sanctuary (Sankaran 1995). The climate of these islands can be defined as humid, tropical coastal. The islands receive rainfall from both the southwest and northeast monsoon, with maximum precipitation between May and December, and the driest period between January and April (Sankaran 1995). The forest type of the Nicobar Islands can be broadly classified as Andaman Tropical Evergreen, Andaman Semi-Evergreen, Littoral Forest and Tidal Swamp Forest (Mangrove), the inland areas being either forested or grasslands, and a significant proportion of the coast being mangroves.

Key Biodiversity 

AVIFAUNA: A total of 128 of birds are known from the Nicobar group of islands (Abdulali 1964, 1967; Das 1971). During his study on the Nicobar Scrubfowl (=Megapode) Megapodius nicobariensis, Sankaran (1998) recorded 57 bird species. Later, Sivakumar and Sankaran (2002) added four more species (Lesser Frigatebird Fregata ariel, Large Hawk Cuckoo Hierococcyx sparverioides, Ashy Drongo Dicrurus leucophaeus, and Eyebrowed Thrush Turdus obscurus) to the checklist. None of them are presently of much conservation concern, but worth monitoring. Perhaps the most important bird is the Nicobar Megapode Megapodius nicobariensis nicobariensis, a subspecies of the Nicobar megapode occuring on seven islands of the Nancowry group: Camorta, Nancowry, Trinkat, Katchall, Teressa, Bompoka, and Tillangchong. The population of this subspecies is between 600 to 2100 breeding pairs (Sankaran 1998), while the other subspecies abbotti is much more common. The Nicobar Bulbul Hypsipetes nicobariensis is exclusive to the Nancowry subgroup. It is facing a threat from the introduced Andaman Red-whiskered Bulbul Pycnonotus jacosus whistleri, which is endemic to Andaman Islands, as both species probably occupy the same ecological niche (Sankaran 1998). The British introduced the Andaman Red-whiskered Bulbul to Comorto in the late 1800s. It is now also present on Nancowry, Trinkat, Katchall, Teresa and Car Nicobar (another IBA). The Nicobar Sparrowhawk Accipiter butleri is endemic to the Nicobar Islands. Ali and Ripley (1987) have recognized two subspecies from Nicobar islands: Katchal Shikra Accipiter badius obsoletus and Car Nicobar Shikra A. badius butleri, while Inskipp et al. (1996) and Grimmett et al. (1998) have recognized only Nicobar Sparrowhawk Accipiter butleri as valid species. Recently, Rasmussen and Anderton (in press) have also considered Accipiter butleri as full species. Sankaran (1998) considers butleri to be endangered. BirdLife International (2001) has listed it as Vulnerable and Restricted Range (Endemic) because it is confined to ‘Nicobar Islands Endemic Bird Area’. The primary threat to this species appears to be habitat loss. There are nine Restricted Range species in the Nicobar Islands (Stattersfield et al. 1998). Except for the Nicobar Parakeet Psittacula caniceps, which has been reported from the islands of Montschall, Kondul and the Great Nicobars (Abdulali 1964), all other species have been reported from this IBA. Sankaran (1998) has listed 37 bird species from these islands. Recently, Rasmussen and Anderton (in press) have upgraded many subspecies to full species. The ‘new’ species occurring in these islands are the Andaman Pompadour Pigeon Treron chloroptera, earlier considered as a subspecies of Treron pompadora. It is still a common bird and Sankaran (1998) found it on all the five islands that constitute this IBA. Similarly, the Nicobar Green Imperial Pigeon Ducula nicobarica, an earlier subspecies of the widely distributed Green Imperial Pigeon Ducula aenea (Ali and Ripley 1987, Grimmett et al. 1998) was also found in all the islands of this site. Both species are not immediately threatened but they have to be considered as Restricted Range species because total habitat available to them is much below 50,000 sq. km (the EBA criteria, see Stattersfield et al. 1998). The Nicobar or Hume’s Brown Hawk-owl Ninox scutulata obscura has become Ninox obscura. It could be a very rare species as Abdulali (1967) did not record it in the Nicobars, and Sankaran (1998) also did not see it in any of the five islands. It could be one of the rarest endemic birds of the Nicobar Islands. More information is required to determine its status.

OTHER KEY FAUNA: The only large terrestrial native mammal is the Andaman Wild Pig Sus scrofa andamanensis. Some people claim that even this was brought in by earlier settlers from wherever they came. Other fauna includes the Nicobar Short-nosed Fruit Bat Cynopterus sphinx scherzeri, and the endemic Nicobar Flying Fox Pteropus faunulus. The unique herpetofaunal diversity of this region includes Cantor’s Pit Viper Cryptelytrops (Trimeresurus) cantori, an endemic and rare species of reptile, which is reported only from two localities Camorta Island and Car Nicobar, and is considered as Vulnerable by IUCN. Another endemic and endangered species, Nicobarese Worm Lizard Dibamus nicobaricum is also reported from this area (Anon. 2001).

Populations of IBA trigger species

Species Season Period Population estimate Quality of estimate IBA Criteria IUCN Category
Nicobar Scrubfowl Megapodius nicobariensis resident  2004  present  A1, A2  Vulnerable 
Nicobar Sparrowhawk Accipiter butleri resident  2004  present  A1, A2  Vulnerable 
Andaman Woodpigeon Columba palumboides resident  2004  present  A2  Near Threatened 
Andaman Cuckoo-dove Macropygia rufipennis resident  2004  present  A2  Near Threatened 
Andaman Boobook Ninox affinis resident  2004  present  A2  Near Threatened 
Nicobar Bulbul Hypsipetes nicobariensis resident  2004  present  A1, A2  Near Threatened 
White-headed Starling Sturnus erythropygius 2004  present  A2  Least Concern 

IBA Monitoring

2013 very high near favourable medium

Human intrusions and disturbance war, civil unrest and military exercises happening now whole area/population (>90%) very rapid to severe deterioration very high

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

Megapodius nicobariensis Nicobar Scrubfowl 1200 64 individuals 6 not assessed

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)  
Tillongchang Island Sanctuary 3,643 is identical to site 1,683  


IUCN habitat Habitat detail Extent (% of site)
Forest   -
Grassland   -
Coastline   -
Artificial - terrestrial   -

Land use

Land-use Extent (% of site)
agriculture -
Notes: Agriculture
fisheries/aquaculture -
Notes: Fisheries
forestry -
Notes: Plantations
nature conservation and research -
Notes: Nature conservation and research
tourism/recreation -
Notes: Tourism and recreation
urban/industrial/transport -
Notes: Transport

Acknowledgements Key contributors: Ravi Sankaran and K. Sivakumar.


Abdulali, H. (1964) The Birds of the Andaman and Nicobar Islands. J. Bombay Nat. Hist. Soc. 61(3): 483-571.

Abdulali, H. (1967) The Birds of the Nicobar Islands, with notes on some Andaman Birds. J. Bombay Nat. Hist. Soc. 64(2): 139-190.

Ali, S. and Ripley, S. D. (1987) Compact Handbook of the Birds of India and Pakistan (Second Edition). Oxford University Press, Delhi.

Anonymous (2001) Reptile CAMP Handbook. Vol. I. Reptiles endemic to India. South Asian Reptile Network, Zoo Outreach Organization, Coimbatore.

BirdLife International (2001) Threatened Birds of Asia: BirdLife International Red Data Book. BirdLife International, Cambridge, U.K.

Das, P. K. (1971) New records of birds from the Andaman and Nicobar Islands. J. Bombay Nat. Hist. Soc. 68: 459-461.

Grimmett, R., Inskipp, C. and Inskipp, T. (1998) Birds of the Indian Subcontinent. Christopher Helm (Publishers) Ltd., London, U.K.

Inskipp, T., Lindsey, N. and Duckworth, W. (1996) An Annotated Checklist of the Birds of the Oriental Region. Oriental Bird Club, U.K.

Rasmussen, P. C. and Anderton, J. C. (in press) Birds of South Asia: the Ripley guide. Lynx Edicions, Barcelona.

Sankaran, R. (1995) The Nicobar Megapode and other endemic Avifauna of the Nicobar Islands status and Conservation. SACON Technical Report 2, Salim Ali Center for Ornithology and Natural History, Coimbatore, India.

Sankaran, R. (1998) An Annotated checklist of the endemic avifauna of the Nicobar Islands. Forktail 13, 17-22.

Sivakumar, K. and Sankaran, R. (2002) New records of birds from the Andaman and Nicobar Islands. Forktail 18: 149-150.

Stattersfield, A. J., Crosby, M. J., Long, A. J. Wege, D. C. (1998) Endemic Bird Areas of the World: Priorities for Biodiversity Conservation. BirdLife Conservation Series No. 7. BirdLife International, Cambridge.

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Recommended citation  BirdLife International (2016) Important Bird and Biodiversity Area factsheet: Tillangchong, Camorta, Katchal, Nancowry and Trinkat. Downloaded from on 27/10/2016

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