Birds which breed further south in Argentina and Uruguay migrate to Bolivia and southern Brazil, (the cerrado etc.

The female lays 3 brown-speckled pale blue-green eggs in a grassy cup nest in tall grass, and several pairs may breed close to each other in suitable areas.

Females have dark-streaked pale brown upperparts and dull yellow underparts.

The call is a sharp te-tsip, and the male's song, given from a perch or in a display flight, is a series of chips, buzzes and trills.

Grassland yellow finches eat seeds and insects, and are usually seen in pairs or small groups.