It inhabits forests and secondary growth, with the greatest concentrations in coastal forests. It incubates its eggs in nest-mounds close to the shore which are built from sand, loam and humus. The species is primarily monogamous, although extra-pair copulations have been observed. In a pair, both the male and female contribute to the mound maintenance. Unpaired mature males build and defend mounds to attract a partner (K. Sivakumar in litt. 2004). Several pairs often share nest-mounds, with a strong hierarchy apparent during egg-laying. Larger mounds tend to have more stable incubation temperatures and the shortest incubation period (c.72 days). Annual hatching success fluctuates widely (e.g. 87% in 1996 cf. 37% in 1997).

Megapodius nicobariensis is endemic to the Nicobar Islands, India (BirdLife International 2001), where it occurs as two races:  M. n. abbotti on Great Nicobar, Little Nicobar, Kondul, Menchal, Treis, Meroe, and M. n. nicobariensis on Camorta, Trinkat, Nancowry, Katchall, Teressa, Bompoka and Tillanchong islands (Sivakumar 2007), with the apparent sighting of a pair on Cubra Island in May 2009, and records from Pilo Milo in May 2011 (A. P. Zaibin in litt. 2012). It was thought to be extinct on Pilo Milo (Sivakumar 2010). Historical reports from Little Andaman, India, and the Cocos Islands, Myanmar, lack substantiating evidence. In 1994, there were estimated to be 2,318-4,056 breeding pairs, but following the tsunami in December 2004 populations disappeared completely from two small islands, Trax and Megapode Island, and the total number of breeding pairs was estimated at 395-790 following surveys in 2006, with the majority on Great Nicobar (203-406) and Little Nicobar (82-164) (Sivakumar 2010). Preliminary assessments since 2006 indicate that although a major interruption to breeding occurred in 2005 and 2006, breeding success had improved (R. Sankaran in litt. 2008); however, some threats, such as the encroachment of plantations, appear to have worsened since the tsunami (Sivakumar 2010). Surveys conducted in 2009-2011 resulted in a population estimate of 376-752 breeding pairs, suggesting that the population has at best remained stable since 2006 (A. P. Zaibin in litt. 2012).

Conservation Actions Underway
It is listed in Schedule I of the Wildlife Protection Act (1972). It occurs in Campbell Bay and Galathea National Parks on Great Nicobar (a Biosphere Reserve), and three wildlife reserves on uninhabited islands. Designation of most of the Nicobars as tribal areas legally prohibits commercial exploitation of natural resources and settlement or ownership of land by non-tribal peoples. Detailed status surveys and ecological studies are on-going (K. Sivakumar in litt. 2005). Permanent monitoring plots have been established to determine population trends (Sivakumar 2007). Surveys of this species, and other taxa, were conducted between January 2009 and August 2011 as part of the project 'Monitoring post-tsunami coastal ecosystem recovery in the Nicobar Islands' (A. P. Zaibin in litt. 2012). The species is one of 15 threatened species prioritised by the Government of India for the preparation of a ‘Species Recovery Plan’ under its ‘Integrated Development of Wildlife Habitats’ programme (K. Sivakumar in litt. 2012).

Conservation Actions Proposed
Continue to monitor inland and coastal populations following the 2004 tsunami; with the aim of reassessing the medium-term impacts after 10 years. Monitor the regeneration of littoral forests. Initiate a conservation awareness programme to reduce hunting. Empower indigenous people to follow alternative livelihood options such as fishing, handicrafts etc. Eradicate and manage invasive species. Include coastal forests free from human settlement in the existing Protected Areas networks and strictly implement the Indian Wildlife (Protection) Act, 1972. Continue to lobby for expansion of the existing protected areas system to encompass wider tracts of coastal forest on Great Nicobar, the Nancowry island group and Little Nicobar. Carry out habitat restoration work on the west coast of Great Nicobar (A. Rahmani in litt. 2012). Review the immunity of indigenous people to hunting regulations, given their changing lifestyles (A. Rahmani in litt. 2012). Conduct surveys for the species in interior forests (A. Rahmani in litt. 2012). Carry out further studies on its breeding biology and habitat use (A. Rahmani in litt. 2012). Study the impacts of changes in land-use patterns and the lifestyles of indigenous peoples (A. Rahmani in litt. 2012). Formulate a management plan (A. Rahmani in litt. 2012). Following losses to the tsunami, restore the infrastructure of the state forest department (A. Rahmani in litt. 2012).