Machaerirhynchus nigripectus Schlegel, 1871

Medium sized aberrant flycatcher; unusually shaped large flattened bill with distinct keel on upper mandible is shaped like an upturned rowing boat. Male nominate race is glossy black above, with bright yellow side of face, black lores; two broad white wingbars formed by tips of median and greater upperwing-coverts, secondaries edged whitish; tail black, white edges and tips on outer feathers; chin, throat and underparts golden-yellow, large black spot or patch in centre of breast; iris dark brown; bill black, sometimes white tip; legs grey-brown to black. Female is like male but duller, with narrow yellow supercilium and black eyestripe, less rich yellow below, smaller black breast patch. Juvenile resembles a dull scruffy adult with brownish feather tips, no breast patch, underparts blotched and mottled with black on dull pale yellow; immature very dull yellow below, breast patch just a few dark feathers. Races exhibit minor plumage variation: female harterti has greyer upperparts than others.