Argentina (B), Bolivia (B), Brazil (NB), Paraguay (B).
Locally in northern and eastern Bolivia (Beni, La Paz and western Santa Cruz), south-western Brazil (southern Mato Grosso and southern Goiás), central Paraguay, north-eastern Argentina (eastern Formosa and eastern Chaco south to Corrientes, Entre Ríos and northern Buenos Aires) and western Uruguay.
 
Population
Estimated population is unknown (2010) and decreasing.
Status NT
Habitat destruction and degradation through conversion to agriculture, intensive cattle-grazing and afforestation with non-native tree genera, and pressure from trappers, are the main threats.
For more information see BirdLife International Species Factsheet.
Rufous-rumped Seedeater (Sporophila hypochroma) [XC51937]
by Bernabe Lopez-Lanus from San Javier, Santa Fe, Argentina (song)
Rufous-rumped Seedeater (Sporophila) [XC45246]
by id from Alrededores de San Javier (12 km al W)_Santa Fe, Argentina (song)
Subspecies
No subspecies.
Molecular evidence suggests that genus is closely related to Oryzoborus, which should perhaps be subsumed within it. Further, that both genera should be placed in the tanager family (Thraupidae). A molecular-genetic study of 17 species in genus, including ten in "capped" group ("capuchinos"), indicated that latter form two clades, a northern clade largely north of R Amazon containing Ruddy-breasted Seedeater (Sporophila minuta) and Chestnut-bellied Seedeater (Sporophila castaneiventris), and a southern clade consisting of present species and Copper Seedeater (Sporophila bouvreuil), Tawny-bellied Seedeater (Sporophila hypoxantha), Dark-throated Seedeater (Sporophila ruficollis), Marsh Seedeater (Sporophila palustris), Chestnut Seedeater (Sporophila cinnamomea) and Black-bellied Seedeater (Sporophila melanogaster). Determination of relationships within the southern clade not possible, as genetic differentiation very low and species are apparently part of a very recent and rapid radiation.