Politically part of India, the Nicobar Islands are the peaks of a submerged mountain range, and comprise some 24 islands (12 inhabited) lying in the Bay of Bengal between the Andaman Islands (EBA 125) and Sumatra (EBA 158). The islands can be divided into three distinct groups: Car Nicobar and Batti Malv in the north, the Nancowry group in the centre (including the main islands of Teressa, Camorta, Trinkat, Nancowry and Katchall), and the Great Nicobar group in the south (including the main islands of Little and Great Nicobar).

The native vegetation can be broadly classified as tropical lowland evergreen rain forest, with mangroves in some coastal areas.

All the EBA's restricted-range species inhabit forest and a few have also been recorded in secondary and man-made habitats.

The avifaunas of the islands are largely similar but there are a few significant differences in the species' distribution patterns (see table): for example, Psittacula caniceps occurs only in the Great Nicobar group, while Hypsipetes nicobariensis is present only in the Nancowry group, and several other species have distinct subspecies on the three different island groups. There are records of restricted-range species from many of the offshore islands but it is doubtful whether some of the tiny ones harbour viable populations (R. W. R. J. Dekker in litt. 1993).

There is some evidence that Megapodius nicobariensis occurred earlier in the twentieth century on some of the Andaman Islands to the north (Little Andaman and Coco Islands, EBA 125) (R. W. R. J. Dekker in litt. 1993), and a further four species are still shared with the Andamans, indicating affinity between these EBAs (see Ripley and Beehler 1989).

Most of the islands in the Nicobar archipelago have been designated as tribal areas where local people have a subsistence lifestyle, but there has been an influx of people from mainland India, resulting in increased pressure on natural resources. Large areas of forest have consequently been felled and some islands now have extensive grasslands (e.g. the Nancowry islands) or coconut plantations (e.g. Car Nicobar, where there is some uncertainty about whether forest species continue to survive). The most immediate threat in the Nicobars is, however, the proposal to make Great Nicobar a free port and to create a dry dock and refuelling base there for international shipping (Sankaran 1995).

All the restricted-range bird species are classified as threatened or Near Threatened, owing to their small ranges and populations, and the continuing threat of habitat destruction. A recent study of Megapodius nicobariensis has shown this species to be more common than once thought (between 4,500 and 8,000 birds: Sankaran 1995), although it has declined in the Nancowry group as a result of forest loss and localized hunting for food and egg collection. Hypsipetes nicobariensis appears to have declined on the Nancowry group, possibly through displacement by the introduced Red-whiskered Bulbul Pycnonotus jocosus (Sankaran 1993a,b). Despite its name, Nicobar Pigeon Caloenas nicobarica is a widespread (Near Threatened) species, also occurring on these islands.

There are a few protected areas in this EBA (covering c.30% of the land area) including Batti Malv, Tillanchang and Megapode islands which are all uninhabited wildlife sanctuaries. Great Nicobar is a Biosphere Reserve, and the designation in 1992 of two large national parks (covering 536 km² of primary forest) will help to secure the future of some of the restricted-range species there. Nevertheless the existing network of protected areas is still considered inadequate to conserve all endemic subspecies and a proposal has been made to redefine the boundaries of the Great Nicobar Biosphere Reserve and to establish a Nancowry Biosphere Reserve to cover four important core areas on Tillanchang, Camorta, Nancowry and Katchall (Sankaran 1995; see also Sankaran 1997).

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 7. Cambridge, UK: BirdLife International.

Recommended citation
BirdLife International (2024) Endemic Bird Area factsheet: Nicobar Islands. Downloaded from https://datazone.birdlife.org/eba/factsheet/138 on 26/12/2024.