Description: A small, compact seedeater 12–13 cm long, with a distinctive short, thick, bright yellow bill in males. Male: slate gray. Wings blackish with a white patch at the base of the primaries and a white band visible in flight. Tail blackish with a diagnostic central white band on the underside. Under-tail coverts chestnut-rufous. Belly white. Lores black. Bill thick and bright yellow. Legs dark. Female: brown and streaked on crown, back, breast, and flanks; mantle with a cinnamon tint. White patch on primaries and white tail band as in the male. Under-tail coverts cinnamon. Bill dull yellow. Juvenile: similar to the female but browner and more streaked. Distinguishes itself from the Greater Yellow-billed Seedeater (C. inornata) by the white band on the wings and tail, bright yellow bill, white belly, and uniform back (the Greater lacks white bands, has a pinkish bill, and the male appears more bluish with a slightly streaked back).

Geographic distribution: Broad Andean distribution from Colombia to Argentina. In Argentina: NOA (Jujuy, Salta, Tucumán, Catamarca), Cuyo, Central Sierras (Córdoba, San Luis), and Sierra de Ventania (Buenos Aires). Occurs between 1,000 and 3,400 m (occasionally higher in the NOA). Resident, with some downslope altitudinal movements in winter.

Habitat: High Andean steppe, ravines and shrubby thickets, cropland edges, montane grasslands, monte areas, and shrublands in populated zones.

Behavior: Active and restless, usually in pairs or small groups; may join mixed flocks with other seedeaters. Forages on the ground or in low vegetation, especially in cortadera grass. Flies low among shrubs. Often perches in the open on rocks or bushes to sing. Voice is a short, harsh trill repeated at intervals. More complex songs combine trills with ascending buzzing notes. Short “tzi”-type calls.

Diet: Mainly seeds (especially composites), also berries and insects. Pecks on the ground and climbs grass stems to take seeds directly from the spike.

Nesting: Cup-shaped nest of plant fibers, lined with hair and wool, placed in shrubs or thickets. Clutch of 2–3 eggs.

Conservation status: Not considered threatened. Common to very common across much of its range; present in modified environments.

Authors of this compilation: Diego Carus and Maria Belén Dri – 06/12/2025