A large seedeater with a very large pinkish bill. Males are brownish-olive above and yellow below with a diffuse but noticeable head pattern; females are brown above and white below with heavy streaking all over the body. Both sexes have a yellow rump that is conspicuous in flight. Found in dry thorn savanna, thorn scrub, and semi-desert, usually in pairs or small groups. The distinctive song consists of series of sliding whistles: several on a higher pitch, then several on a lower pitch, several on the higher pitch, and so on. Separated from all other seedeaters in its range by its larger size and heavier pale bill.