The black-billed seed finch is a species of bird in the family Thraupidae. It is found in the western Amazon Basin.
Region
Western Amazon Basin
Typical Environment
Occurs in lowland floodplains of eastern Ecuador, northern Peru, and adjacent western Brazil, with local presence in riverine Colombia. It favors seasonally flooded várzea, river islands, and tall grasslands near large rivers. The species also uses edges of secondary growth, marshy fields, and shrubby clearings. Local movements often track seeding grasses and changing water levels.
Altitude Range
0–600 m
Climate Zone
Tropical
Ease of Keeping
Beginner friendly: 2/5
A small seed-eating tanager of riverine lowlands, the black-billed seed finch is notable for its entirely dark bill, unlike many seedeaters with pale bills. Males are mostly glossy black, while females are warm brown and more cryptic. It frequents floodplain grasses and shrubby edges, often moving with seasonal water levels. Its clear, melodious whistles make it a target for the cage-bird trade in some areas.
Temperament
skulking and wary
Flight Pattern
short rapid wingbeats, low over grasses
Social Behavior
Usually seen singly or in pairs during the breeding season, becoming loosely gregarious where grasses are seeding. Males sing from exposed perches along river edges or in tall grass. Nests are small cups placed low in dense vegetation, and both parents attend the young.
Migratory Pattern
Resident
Song Description
Song is a series of clear, whistled phrases with sweet, ringing notes and short trills. Calls include sharp chips and thin tseet notes used to keep contact in dense cover.
Plumage
Strongly dimorphic: male largely glossy black with a thick, all-black conical bill; female warm brown to cinnamon-brown above with paler underparts. Both sexes show plain wings lacking bold bars and a clean, uniform look. Feathers are smooth with minimal patterning, aiding camouflage in grasses for the female.
Diet
Primarily consumes seeds of grasses and sedges, crushing them with its powerful conical bill. It takes fallen seeds on the ground and plucks seedheads directly from standing grasses. During breeding it may supplement with small insects for added protein.
Preferred Environment
Forages in tall riverine grasses, along levees, sandbars, and on the edges of seasonally flooded forests. Often feeds at the ecotone between grassy clearings and shrubby stands near water.
