Birds of Singapore
by the Bird Society of Singapore
Sula dactylatra
Family: Boobies and Gannets · Status: Very rare visitor · Size: 74–86 cm · Conservation: Least Concern
Pantropically between roughly 30 degrees north and 30 degrees south of the equator, across the Indian, Pacific and Atlantic Oceans.
Adult all-white with yellow bill and black primaries, secondaries and tail. Face blue-black. Immature has brown upperparts and underwings with a conspicuous white collar. Separated from Red-footed Booby at all ages by greyish-yellow feet (not red), yellow bill (not bluish-grey), and black tertials; adult white morph Red-footed Booby shows a black patch on under primary coverts absent in Masked Booby. Separated from Brown Booby by adult all-white body; immature told from Brown Booby by the white collar and breast.
Open seas, rarely in coastal waters.
Strong flyer that forages over deep open ocean, often hundreds of kilometres from land. Feeds by plunge-diving, sometimes from considerable heights. The most strictly pelagic of the boobies recorded in Singapore.