Dull-colored Grassquit

The dull-colored grassquit is 10.5 to 11.5 cm (4.1 to 4.5 in) long and weighs an average of 11.2 g (0.40 oz). 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. 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.

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 400 and 2,000 m (1,300 and 6,600 ft) but mostly above 700 m (2,300 ft). …

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.