The Wedge-tailed Grass-Finch is a resident of grasslands from Costa Rica south to northern South America, and it also occurs from central and eastern Brazil south to Argentina. Wedge-tailed Grass-Finches are brown above with heavy black streaking and have dusky wings with a yellow bend, a white throat and a light brown breast. The tail is very long, and is highly graduated: the central rectrices may be twice as long as the outermost pair of rectrices. The male sings from a relatively exposed site, such as on a fence post or the crown of a shrub. Otherwise Wedge-tailed Grass-Finches are secretive birds that are usually forage on the ground in tufts of grass, where they can be difficult to see.