The Nicobar pigeon moves around in flocks during the day, spending the majority of its time on the forest floor, foraging for seeds, berries, large nuts, fruits and insects (2) (3). Like other doves and pigeons, it drinks by submerging its beak and sucking up water, rather than by sipping (2).
The Nicobar pigeon is monogamous and pairs typically mate for life (2). During courtship, the male performs a bowing display in which the plumage is erected. Similarly, the neck plumage may also be raised during aggressive interactions (10).
The Nicobar pigeon probably breeds year-round. Once a nesting site has been selected, usually in a tree or bush a few metres off the ground, a nest is constructed. The nest consists of an untidy collection of twigs, and is often accompanied by other nests in the same tree (2) (10).
The female Nicobar pigeon lays a single white egg, which is long and elliptical in shape. The egg is incubated by both adults and hatches after around two and a half weeks. The chick is initially helpless and fed a rich crop milk fluid, regurgitated by the adults, who continue to tend the chick until it fledges at about three months (2) (10).