Black-and-tawny Seedeater

The black-and-tawny seedeater is about 10 cm (3.9 in) long. It is one of the smallest of its genus. It has a short, thick bill with a rounded culmen. The species is sexually dimorphic. Adult males have a black cap down to just past the eye. Their face and nape are tawny-cinnamon except for a thin black line down the center of the nape. Their upper back is black and their lower back and rump are dark tawny. Their tail is black. Their wings are black with white edges on the greater coverts and tertials. Their wing's primaries have white bases that show as a very small patch on the folded wing. Their throat and underparts are cinnamon-tawny. Females have an olive-brown head and upperparts. Their wings and tail are dusky olive with paler feather edges. Their throat is pale yellowish, their breast olive-tinged yellowish, and the rest of their underparts off-white to pale cinnamon. Both sexes have a dark brown iris. Males have a blackish bill and black legs; females have a horn-colored bill and dusky legs.

The black-and-tawny seedeater is found from eastern Bolivia's Santa Cruz and Beni departments east into southwestern Brazil's Mato Grosso and far northern Mato Grosso do Sul states. It inhabits grassy landscapes including Cerrado, tall grasslands near water, and savanna at elevations up to 500 m (1,600 ft).

The black-and-tawny seedeater feeds on grass seeds. It typically feeds while clinging to stems up to about 1.5 m (5 ft) above the ground. In what is thought to be its non-breeding season it often gathers in flocks that can exceed 100 individuals.