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Unicolored Blackbird - BirdForum Opus

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Male, nominate subspecies
Photo © by birdclub
Pantanal, Brazil, 15 September 2007
Agelasticus cyanopus


Length 18–21 cm (17-8¼ in)
A typical icterid blackbird, with an appropriate name, at least for the male, which is totally black.
The female, however, is anything but unicolored, with a yellow streaked breast, rufous-olive back, and brown head. Her wings and tail are the only black parts.


Female, nominate subspecies
Photo © by Stanley Jones
Entre Ríos Province, Argentina, 2 October 2019

Although males are all black, females vary dramatically depending on the subspecies. Some have bright yellow underparts (nominate race A. c. cyanopus); some are blackish, with an olive-yellow wash (A. c. unicolor); and some are simply olive-yellow (A. c. atroolivaceus).


South America: found in Bolivia, Brazil, Paraguay and Argentina


Formerly placed in Chrysomus. Lopes (2017)[5] recommended recognizing two species, A. cyanopus and A. atroolivaceus (including unicolor as a subspecies).


Juvenile male
Photo © by Stanley Jones
Entre Ríos Province, Argentina, 2 October 2019

Three subspecies currently recognized[1][5]:

  • A. c. unicolor:
  • Northeastern Brazil (Amapá to Pará and northwestern Maranhão) south through central Brazil to northwestern Paraná and western São Paulo; intergrades with atroolivaceus in southern São Paulo
  • A. c. atroolivaceus:
  • Eastern Brazil, from Minas Gerais and southwestern Bahia south to coastal southeastern Brazil (Espírito Santo to São Paulo); intergrades with unicolor in southern São Paulo
  • A. c. cyanopus:

Former subspecies A. c. xenicus is a junior synonym of A. c. unicolor.
Former subspecies A. c. beniensis is now considered a junior synonym of A. c. cyanopus.
Ranges of A. c. unicolor and A. c. atroolivaceus expanded.





Their diet consists mostly of insects, small vertebrates and seeds. Possibly also nectar.


  1. Clements, J. F., T. S. Schulenberg, M. J. Iliff, S. M. Billerman, T. A. Fredericks, B. L. Sullivan, and C. L. Wood. 2019. The eBird/Clements Checklist of Birds of the World: v2019. Downloaded from http://www.birds.cornell.edu/clementschecklist/download/
  2. Avibase
  3. Fraga, R. (2020). 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 https://www.hbw.com/node/62313 on 17 February 2020)
  4. Birdforum post related to subspecies taxonomy of this species.
  5. Lopes, L. E. (2017) Variation of plumage patterns, geographic distribution and taxonomy of the Unicolored Blackbird (Aves: Icteridae). Zootaxa 4221: 431–456

Recommended Citation

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