The wedge-tailed grass finch is a species of bird in the family Thraupidae; it was formerly placed in the Emberizidae. It is found in Argentina, Bolivia, Brazil, Colombia, Costa Rica, Ecuador, French Guiana, Guyana, Panama, Paraguay, Peru, Suriname, Uruguay, and Venezuela.
Region
South America and southern Central America
Typical Environment
Occurs from Panama and Costa Rica south through northern and central South America to Bolivia, Brazil, Paraguay, Uruguay, and northern Argentina, also in the Guianas and the Orinoco and Amazon basins. It inhabits open grassy habitats including savannas, cerrado, pastures, pampas-like grasslands, and marsh edges. Often found in disturbed or grazed fields with tall, rank grasses and scattered shrubs. It avoids dense forest, keeping to edges, clearings, and riverine grasslands.
Altitude Range
Sea level to 1800 m
Climate Zone
Tropical
Ease of Keeping
Beginner friendly: 2/5
Despite its name, this tanager-relative was formerly placed with buntings and sparrows (Emberizidae) but is now in Thraupidae. It favors tall grasslands and savannas where its long, wedge-shaped tail helps with balance while clambering through stems. Males often sing from exposed grass tops, making an otherwise skulking bird easier to spot.
Temperament
skulking but often perches conspicuously to sing
Flight Pattern
short low flights with rapid wingbeats between grass clumps
Social Behavior
Usually seen singly, in pairs, or small family groups, moving through dense grasses. Nests are cup-shaped and placed low in tall grass or shrubs. Likely monogamous, with males singing from elevated perches during the breeding season.
Migratory Pattern
Partial migrant
Song Description
Song is a series of thin, tinkling trills and buzzy phrases delivered from exposed stems. Calls include sharp ticks and soft chips used to maintain contact in dense cover.
Plumage
Olive-brown upperparts with subtle streaking, a grayish face, and warm buff underparts that may be paler on the throat and belly. Tail is long, narrow, and graduated, giving a wedge-shaped appearance. The supercilium is pale buff, with a slightly dusky eye-line and malar area.
Diet
Feeds primarily on grass seeds and small seeds of forbs, supplemented by insects such as beetles, grasshoppers, and caterpillars. In the breeding season it increases insect intake for protein. It gleans from seed heads, picks items from the ground, and occasionally sallies short distances for flushed prey.
Preferred Environment
Forages within tall, rank grasses, at field margins, and along marshy edges where seed heads are abundant. Often uses lightly grazed pastures and fallow fields with mixed grass height.
