Family New World Blackbirds (Icteridae)

Least Concern

Unicolored Blackbird (Agelasticus cyanopus)


French: Carouge unicolore German: Einfarbstärling Spanish: Varillero negro

Agelaius cyanopus


, 1819,



Closely related to A. xanthophthalmus. Races rather distinct, based on differences in female plumages, and has been suggested that more than one species is involved#R; research needed (specimen material in museums seemingly sparse). Four subspecies recognized.

Subspecies and Distribution
  • A. c. xenicus (Parkes, 1966) – Para Blackbird – NE Brazil (Amapá, NE Pará and N Maranhão); possibly also French Guiana.
  • A. c. beniensis (Parkes, 1966) – N Bolivia (Beni).
  • A. c. cyanopus (Vieillot, 1819) – Unicolored Blackbird – E Bolivia (Santa Cruz) and C & S Brazil (S from Mato Grosso and W São Paulo) S across Paraguay to NE Argentina (S to NE Buenos Aires).
  • A. c. atroolivaceus (Wied, 1831) – Rio de Janeiro Blackbird – coastal plain of E Brazil from Espírito Santo S to Paraná.
  • A few individuals reported from SW Amazonian Peru may belong to race beniensis; reported also from N Bahia, in E Brazil (presumably race atroolivaceus).

    Descriptive notes

    c. 18–21 cm; male average 40·6 g, female 37·4 g. A slender-billed, long-tailed icterid. Male nominate race is entirely black with very slight bluish gloss; iris dark brown;... read more


    Song, apparently by both sexes, alternating liquid “shr-r-le” rattles with series of repeated... read more


    Permanent marshes with abundant emergent vegetation, such as sedge (Cyperus), Thalia... read more

    Food and feeding

    Arthropods (mostly insects), small vertebrates and seeds; reported as taking nectar from inflorescences of the vine Combretum... read more


    Season Oct–May (mainly Nov–Feb) in NE Argentina; more than one brood attempted per season. Breeds solitarily or in small colonies of up to... read more


    Apparently sedentary.

    Status and conservation

    Not globally threatened. Locally numerous; rare and local in Rio Grande do Sul (S Brazil) and Uruguay. Appears to be locally abundant particularly in Bajo Chaco (Paraguay),... read more

    Recommended citation

    Fraga, R. (2019). Unicolored Blackbird (Agelasticus cyanopus). In: del Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. & de Juana, E. (eds.). Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona. (retrieved from on 6 December 2019).