The Tongan Whistler lives in forest on Tonga's Vava'u Islands. Males and females have clearly different plumage.
The male has a black head, throat, and upper breast, with a yellow collar that joins the yellow underparts and yellowish-olive upperparts. The female has an olive-gray crown, a yellowish-olive collar, and a white upper throat.
It forages mainly in the forest understory for insects and sometimes small lizards. The source places its breeding season from July to September.
An extinction-risk assessment has not been added yet.