The Rusty-collared Seedeater is a relatively large Sporophila, and occurs in south central South America. The male is very distinctive, with prominent white lores and a white spot below the eye that contrast with the black crown; a broad buffy or white collar across the neck and nape; a black breast band; and cinnamon buff flanks and rump. By the standards of female Sporophila, which usually have nondescript plumages that vary little from one species to another, the female Rusty-collared is relatively distinctive: primarily buffy brown, but with a contrasting white throat, and with relatively well-marked wingbars and a whitish patch at the base of the primaries. The Rusty-collared Seedeater occurs in wet grasslands, and grasses and shrubs bordering ponds. The Rusty-collared Seedeater usually is found in pairs or in small groups, and unlike many species of Sporophila, it only rarely associates with other seedeaters.