The dull-colored grassquit (Asemospiza obscura) is a small bird in the family Thraupidae, the tanagers and allies. It is found in Argentina, Bolivia, Brazil, Colombia, Ecuador, Paraguay, Peru and Venezuela.Remsen, J. V., Jr., J. I. Areta, E. Bonaccorso, S. Claramunt, D. F. Lane, L, N. Naka, M. B. Robbins, F. G. Stiles, and K. J. Zimmer. Version 25 July 2026. Species Lists of Birds for South American Countries and Territories. South American Classification Committee associated with the International Ornithologists' Union. https://www.museum.lsu.edu/~Remsen/SACCCountryLists.htm retrieved 25 July 2026

Taxonomy and systematics

The dull-colored grassquit was formally described in 1837 with the binomial Emberiza obscura. For much of the twentieth century it was placed in the genus Sporophila but by the early twenty-first it had been transferred to Tiaris.Remsen, J. V., Jr., J. I. Areta, E. Bonaccorso, S. Claramunt, D. F. Lane, L, N. Naka, M. B. Robbins, F. G. Stiles, and K. J. Zimmer. Version 25 July 2026. A classification of the bird species of South America. South American Classification Committee associated with the International Ornithologists' Union. https://www.museum.lsu.edu/~Remsen/SACCBaseline.htm retrieved 25 July 2026 Finally, based on studies published in 2014 and 2015, in 2016 Burns et al. erected the genus Asemospiza with the sooty grassquit (A. fuliginosa) as the type species and including the dull-colored grassquit. The genus is closely related to Darwin's finches.

The dull-colored grassquit has these four subspecies:

A. o. haplochroma (Todd, 1912) A. o. pauper (Berlepsch & Taczanowski, 1884) A. o. obscura (d'Orbigny & Lafresnaye, 1837) A. o. pacifica (Koepcke, 1963)

Description

The dull-colored grassquit is long and weighs an average of . The sexes have the same plumage. Adults of the nominate subspecies A. o. obscura have a brownish head and upperparts. They have thin, pale supercilium, a darker line through the eye, and pale crescents above and below the eye. Their throat, breast, and upper flanks are grayish brown and their belly paler. Its more northerly population has a darker breast than more southerly birds. They have a dark brown iris, a dark bill with a yellowish horn base to the mandible, and brownish legs.Jaramillo, A. (2020). Dull-colored Grassquit (Asemospiza obscura), version 1.0. In Birds of the World (J. del Hoyo, A. Elliott, J. Sargatal, D. A. Christie, and E. de Juana, Editors). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bow.ducgra2.01 retrieved September 2, 2026

Subspecies A. o. haplochroma is the darkest of the four. It is essentially all brownish with little contrast between the upper- and underparts. It alone has an entirely dark bill. The population of A. o. pauper in Colombia and Ecuador has a pale brown breast, buffy flanks, and a pale cream belly; its bill has a dark maxilla and a pale mandible. In the south its breast is grayish and both its flanks and belly pale cream. A. o. pacifica is large and pale and similarly colored to the southern A. O. pauper.

Distribution and habitat

The subspecies of the dull-colored grassquit are found thus:

A. o. haplochroma: northern Colombia's isolated Sierra Nevada de Santa Marta; Venezuelan Coastal Range from Carabobo to Miranda; northeastern Venezuela in southwestern Sucre and northern Monagas; Venezuelan Andes from western Mérida and Táchira south through most of the Colombian Andes A. o. pauper: from Nariño Department in far southwestern Colombia south on the western Andean slope through Ecuador into Peru, where it is on the western slope south to northern Huánuco Department and on the eastern slope in San Martín and Loreto departments A. o. obscura: eastern Andean slope intermittently from San Martín south through Bolivia into northwestern Argentina to Tucumán Province and east across southern Bolivia into western Paraguay, Chaco Province in northern Argentina, and slightly into southwestern Brazil's Mato Grosso A. o. pacifica: Peruvian coastal plain and foothills from Ancash Department south to Arequipa Department

The dull-colored grassquit inhabits mostly open landscapes including forest and woodland edges and shrubby clearings, roadside thickets, dry scrublands, and gardens. In elevation in Venezuela it is found between but mostly above . It is found below in Colombia, mostly below in Ecuador, and between in Peru.

Behavior Movement

The dull-colored grassquit is a year-round resident in most of its range. It is probably non-breeding in far eastern Bolivia, Paraguay, and Argentina's Chaco. According to the South American Classification Committee it is solely a non-breeding visitor to Brazil. It is thought to wander seasonally in Venezuela but details are not known.

Feeding

The dull-colored grassquit feeds on seeds, especially those of Panicum grasses. It feeds on the ground or by landing on grass to bend the seedhead down, and often within some cover. It usually forages singly or in pairs and sometimes in small flocks.

Breeding

The dull-colored grassquit breeds during the first half of the year in Ecuador. Its season includes January and February in Bolivia and Argentina and its seasons elsewhere are not known. Its nest is a dome with a side entrance, made from plant fibers, and usually with a "roof" over the entrance. It is typically in a branch fork of a small tree or bush within about of the ground. The clutch is three or four eggs that are whitish with pale and dark brown speckles. The incubation period, time to fledging, and details of parental care are not known.

Vocalization

The dull-colored grassquit's song is "explosive and buzzy, e.g. zeetig, zeezeezig with many variants". Its call is "a high-pitched ti".

Status

The IUCN has assessed the dull-colored grassquit as being of Least Concern. It has a very large range; its population size is not known but is believed to be increasing. No immediate threats have been identified. It is considered "[v]ery spotty and unpredictable in occurrence" in Venezuela and "uncommon" along the Peruvian coast and western slope and "rare but widespread" on the eastern. In Colombia it is "fairly common but often very hard to identify with certainty". (Many records attributed to the sooty grassquit are probably of the dull-colored.Rising, J. D. and A. Jaramillo (2020). Sooty Grassquit (Asemospiza fuliginosa), version 1.0. In Birds of the World (J. del Hoyo, A. Elliott, J. Sargatal, D. A. Christie, and E. de Juana, Editors). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bow.soogra2.01 retrieved September 2, 2026)

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