Birds of Singapore
by the Bird Society of Singapore
Sula leucogaster
Family: Boobies and Gannets · Status: Very rare visitor · Size: 73–83 cm · Conservation: Not Evaluated
Occurs across tropical and subtropical Indian, Pacific and Atlantic Oceans; wanders widely outside breeding seasons to the Indian subcontinent and Southeast Asia.
Adult has dark brown plumage with sharply contrasting white lower breast to vent and mostly white underwing coverts. Juvenile has paler brown plumage and variably mottled, dusky-brownish lower breast; the contrast between belly and chest is reduced compared to adults. Separated from Masked Booby by all-dark brown upperparts; Masked Booby juvenile has a pale white breast and a conspicuous white collar. Separated from brown morph Red-footed Booby by sharply demarcated white belly and clearly defined pale underwing coverts; immature Red-footed Booby shows a dark breast band surrounded by lighter brown.
Open seas and coastal waters; sometimes shallower inshore waters.
More regularly encountered over shallow inshore waters than other booby species. Feeds by plunge-diving and sometimes observed roosting on buoys and vessel structures.