Sulphur-bellied Whistler

The sulphur-bellied whistler, also called the sulphur-vented whistler, is a thick-billed songbird about the size of a sparrow. Adults have uniform rich-brown upperparts and whitish underparts, with a yellow wash strongest on the lower belly and at the base of the undertail. Juveniles have a grey head and rufous-toned plumage. Within its restricted range, the yellow vent is its most useful visible feature (eBird/Merlin identification account).

This resident is endemic to Sulawesi’s forested foothills and mountains. Pairs frequently join mixed-species feeding flocks in the understorey and subcanopy. The song begins with three or four whistles, often held at one pitch, and finishes with a forceful rising whip note. The species has also appeared in literature as the Celebes mountain whistler, Celebes whistler and yellow-vented whistler. The sources opened gave no verified diet, nest, clutch or incubation details (eBird/Merlin; Wikipedia nomenclatural account).