Dull-colored Grassquit (Tiaris obscurus) - HBW 16, p. 669

Taxonomy: Emberiza obscura d’Orbigny and Lafresnaye, 1837, Chiquitos, Bolivia.
Genus may belong in tanager family (Thraupidae); appears to be part of a clade which also includes several Caribbean genera (Euneornis, Loxipasser, Melopyrrha, Loxigilla, Melanospiza), Bananaquit (Coereba flaveola), and “Darwin’s finches” (Certhidea, Platyspiza, Pinaroloxias, Camarhynchus, Geospiza). Molecular data suggest that genus as currently constituted is polyphyletic; further research required. This species was previously included in genus in Sporophila, but skeletal features, nest type, song and molecular data indicate that it is better placed in present genus, and that it is sister to T. fuliginosus. Taxonomy complex: a detailed study of geographical variation of this species identified six diagnosable populations, each of which could be considered a race; of the currently recognized races, however, pacificus and haplochroma correspond to two of the six aforementioned populations, while nominate and pauper incorporate the remaining four. The six identified populations are: those in range of haplochroma (as listed below); population from extreme S Colombia and Ecuador (currently part of pauper); birds of dry N valleys of Peru, in valleys of R Marañón and R Huallaga (currently part of pauper); those in range of pacificus (as listed below); non-coastal regions in Peru, S to La Paz, in Bolivia (currently part of nominate); and E slope from N Bolivia S to N Argentina (currently part of nominate). Thorough review required. Pending full revision, four subspecies recognized.