The Black-breasted Parrotbill (Paradoxornis flavirostris) is a 19 cm long, large, thick-billed parrotbill with black patches on the head-sides and throat. Formerly considered a distinct family, the parrotbills are now placed with the typical warblers in the Sylviidae (Jønsson & Fjeldså 2006).

The bird is more or less brown all over, with an extensive black area on upper breast and uniform rufous-buff remainder of underparts. The similar Spot-breasted Parrotbill, a close relative, has arrow-shaped spotting on breast and pale buff underparts. The voice is a gruff howh, jeehw or jahw, the song a rhythmic series, aw jahw jahw jahw and uhwi uhwi uhwi uhwi. Alternatively, a higher-pitched wi chi'chi'chi'chi'chi, wi yi'yi'yi'yi'yi; wi'uwi-uwi-uwi wi chu-chu-chu is given.(BLI 2006)

Paradoxornis flavirostris is endemic to the Indian subcontinent and in modern times possibly the country of India, where it is known from the plains and foothills of the Brahmaputra valley in Arunachal Pradesh and Assam. Historically, it was also recorded in Bangladesh and possibly eastern Nepal. It used to be a fairly widespread and locally common species. There are, however, recent records from only three locations, one in Arunachal Pradesh and two in Assam, at one of which it appears to be common. There are les than 10.000 mature individuals believed to remain in the wild.(BLI 2006)