Abstract
The Unicolored Blackbird Agelasticus cyanopus (Vieillot, 1819) is a marsh bird with four allopatric subspecies restricted to lowlands in South America east of the Andes. I conducted a taxonomic revision of the species based on analysis of external morphological characters of 288 study skins, including all types available. My revision shows that: 1) Leistes unicolor Swainson, 1838, is a senior synonym of A. c. xenicus (Parkes, 1966) and, therefore, the correct name of the taxon should be A. c. unicolor (Swainson, 1838); 2) the range of A. c. unicolor (Swainson, 1838) is much wider than previously thought, extending from the mouth of the Rio Amazonas to the state of São Paulo, in southeastern Brazil, where it intergrades with A. c. atroolivaceus (zu Wied-Neuwied, 1831); 3) A. c. atroolivaceus extends its range well beyond the coast of Rio de Janeiro, reaching the coast of São Paulo, the central part of Minas Gerais, Bahia and Espírito Santo; and 4) specimens attributed to A. c. beniensis are highly variable, so this name must be considered a subjective junior synonym of the nominotypical taxon. Under the Biological Species Concept, two broadly parapatric species should be recognized, A. cyanopus and A. atroolivaceus (including unicolor as a subspecies). Under the Phylogenetic Species Concept or the General Lineage Concept of Species, the best taxonomic treatment is to recognize three species: A. cyanopus, A. atroolivaceus, and A. unicolor.
References
Allen, J.A. (1889) On the Maximilian types of South American birds in the American Museum of Natural History. Bulletin of the American Museum of Natural History, 2, 209–321.
Azara, F. (1802) Apuntamientos para la Historia Natural de los Páxaros del Paragüay y Rio de la Plata, vol. 1. Imprenta de la Viuda de Ibarra, Madrid, Spain, xx + 534 pp.
Baldwin, S.P., Oberholser, H.C. & Worley, L.G. (1931) Measurements of birds. Scientific Publications of the Cleveland Museum of Natural History, 5, 1–164.
https://doi.org/10.5962/bhl.title.60247Belton, W. (1994) Aves do Rio Grande do Sul, Distribuição e Biologia. Editora Unisinos, São Leopoldo, Brazil, 584 pp.
Benson, C.W. (1999) Type Specimens of Bird Skins in the University Museum of Zoology, Cambridge, United Kingdom. Cambridge University Museum of Zoology, Cambridge, UK, 221 pp.
BirdLife International. (2015) BirdLife's online World Bird Database: the site for bird conservation. Available from http://www.birdlife.org (accessed on April 2015)
Bonaparte, C.L. (1850) Conspectus Generum Avium, vol. I.E.J. Brill Academiae Typographum, Lugdunum, The Netherlands, 543 pp.
https://doi.org/10.5962/bhl.title.70841Bornschein, M.R. & Reinert, B.L. (1997) Acrescido de marinha em Pontal do Paraná: uma área a ser conservada para a manuteção das aves dos campos e banhados do litoral do Paraná, sul do Brasil. In: Milano, M.S. (Ed.), UNILIVRE. Anais do I Congresso Brasileiro de Unidades de Conservação, vol. 2, Curitiba, Brazil, pp. 875–889.
Bornschein, M.R., Reinert, B.L. & Pichorim, M. (1994) Sobre Agelaius cyanopus no litoral do Paraná (Icteridae, Aves). I. Registros e subespécies. In: Ricci, C., Castro, C.B., Pessôa, L.M., Gonzaga, L.A.P., Couri, M.S. & Leite, S.J.T. (Eds.), XX Congresso Brasileiro de Zoologia—Resumos. Museu Nacional, Universidade Federal do Rio de Janeiro, Sociedade Brasileira de Zoologia, Rio de Janeiro, Brazil, pp. 115–115.
Cadena, C.D., Cuervo, A.M. & Lanyon, S.M. (2004) Phylogenetic relationships of the Red-bellied Grackle (Icteridae: Hypopyrrhus pyrohypogaster) inferred from mitochondrial DNA sequence data. The Condor, 106, 664–670.
https://doi.org/10.1650/7471Cadena, C.D., Gutiérrez-Pinto, N., Dávila, N. & Chesser, R.T. (2011) No population genetic structure in a widespread aquatic songbird from the Neotropics. Molecular Phylogenetics and Evolution, 58, 540–545.
https://doi.org/10.1016/j.ympev.2010.12.014Cracraft, J. (1983) Species concept and speciation analysis. Current Ornithology, 1, 159–187.
https://doi.org/10.1007/978-1-4615-6781-3_6de Queiroz, K. (1998) The General Lineage Concept of species, species criteria, and the process of speciation: a conceptual unification and terminological recommendations. In: Howard, D.J. & Berlocher, S.H. (Eds.), Endless Forms: Species and Speciation. Oxford University Press, Oxford, UK, pp. 57–75.
de Queiroz, K. (2005) Different species problems and their resolution. BioEssays, 27, 1263–1269.
https://doi.org/10.1002/bies.20325de Queiroz, K. (2007) Species concepts and species delimitation. Systematic Biology, 56, 879–886.
https://doi.org/10.1080/10635150701701083Dickinson, E.C. (Ed.) (2003) The Howard and Moore Complete Checklist of the Birds of the World, 3rd ed. Princeton University Press, Princeton, USA, 1039 pp.
Dickinson, E.C. & Christidis, L. (Eds.) (2014) The Howard and Moore Complete Checklist of the Birds of the World, 4th ed., vol. 2, Passerines. Aves Press, Eastbourne, UK, lii + 752 pp.
Dornas, T. & Pinheiro, R.T. (2011) Aves coligidas por José Hidasi e Manoel Santa-Brigida na Amazônia Tocantinense: implicações para a distribuição geográfica das aves amazônicas brasileiras. Revista Brasileira de Ornitologia, 19, 276–301.
Ferolla, M.I. (1983) Agressividade de Agelaius ruficapillus Vieillot, 1819, e Agelaius cyanopus, Vieillot, 1819, durante o período reprodutivo (Icteridae, Aves). In: Carnevalli, N. (Ed.), X Congresso Brasileiro de Zoologia—Resumos. Universidade Federal de Minas Gerais, Belo Horizonte, Brazil, pp. 333–333.
Fraga, R.M. (2011) Family Icteridae (New World Blackbirds). In: del Hoyo, J., Elliott, A. & Christie, D. (Eds), Handbook of the Birds of the World, vol. 16, Tanagers to New World Blackbirds. Lynx Edicions, Barcelona, Spain, pp. 684–810.
Gyldenstolpe, N. (1945) A contribution to the ornithology of northern Bolivia. Kungliga Svenska Vetenskapsakademiens Handlingar, 23, 1–301.
Hellmayr, C.E. (1937) Catalogue of birds of the Americas and the adjacent islands in Field Museum of Natural History, part X, Icteridae. Field Museum of Natural History Publications, Zoological Series, 13, 228–228.
ICZN (1999) International Code of Zoological Nomenclature, 4th ed. The International Trust for Zoological Nomenclature, London. UK. Available from http://www.iczn.org/iczn/index.jsp (accessed on April 2015)
Irwin, R.E. (1994) The evolution of plumage dichromatism in the New World blackbirds: social selection on female brightness. The American Naturalist, 144, 890–907.
https://doi.org/10.1086/285717Jaramillo, A. & Burke, P. (1999) New World Blackbirds: the Icterids. Princeton University Press, Princeton, USA, 431 pp.
Johnson, N.K., Remsen, J.V. Jr. & Cicero, C. (1999) Resolution of the debate over species concepts in ornithology: a new comprehensive biologic species concept. In: Adams, N.J. & Slotow, R.H. (Eds.), Proceedings of the 22th International Ornithological Congress. BirdLife South Africa, Durban, South Africa, pp. 1470–1482.
Lanyon, S.M. (1994) Polyphyly of the blackbird genus Agelaius and the importance of assumptions of monophyly in comparative studies. Evolution, 48, 679–693.
https://doi.org/10.2307/2410478Lanyon, S.M. & Omland, K.E. (1999) A molecular phylogeny of the blackbirds (Icteridae): five lineages revealed by cytochrome-b sequence data. The Auk, 116, 629–639.
https://doi.org/10.2307/4089324LeCroy, M. (2013) Type specimens of birds in the American Museum of Natural History, part 11. Passeriformes: Parulidae, Drepanididae, Vireonidae, Icteridae, Fringillinae, Carduelinae, Estrildidae, and Viduinae. Bulletin of the American Museum of Natural History, 381, 1–155.
https://doi.org/10.1206/832.1Lopes, L.E., D'Angelo Neto, S., Leite, L.O., Moraes, L.L. & Capurucho, J.M.G. (2010) Birds from Rio Pandeiros, southeastern Brazil: a wetland in an arid ecotone. Revista Brasileira de Ornitologia, 18, 267–282.
Lopes, L.E. & Gonzaga, L.A.P. (2012) Clinal pattern of morphological variation in Sakesphorus luctuosus (Lichtenstein, 1823), with comments on the enigmatic Sakesphorus hagmanni Miranda-Ribeiro, 1927 (Passeriformes: Thamnophilidae). Zootaxa, 3569, 41–54.
Lopes, L.E. & Gonzaga, L.A.P. (2016) Morphological data support the recognition of four species in the genus Sirystes Cabanis & Heine, 1859 (Aves: Tyrannidae). Zootaxa, 4127 (3), 401–431.
https://doi.org/10.11646/zootaxa.4127.3.1Lopes, L.E., Malacco, G.B., Vasconcelos, M.F., Carvalho, C.E.A., Duca, C., Fernandes, A.M., D'Angelo Neto, S. & Marini, M.Â. (2008) Aves da região de Unaí e Cabeceira Grande, noroeste de Minas Gerais, Brasil. Revista Brasileira de Ornitologia, 16, 193–206.
Lowther, P.E., Fraga, R., Schulenberg, T.S. & Lanyon, S.M. (2004) Nomenclatural solution for a polyphyletic Agelaius. Bulletin of the British Ornithologist's Club, 124, 171–177.
Mayr, E. (1969) Principles of Systematic Zoology. Tata McGraw-Hill Publishing Company, New Delhi, India, 428 pp.
Merrem, B. (1826) C[assicus] T. hybridus. In: Ersch, J.S. & Gruber, J.G. (Eds), Allgemeine Encyclopädie der Wissenschaften und Künste, vol. 15. Johann Friedrich Gleditsch, Leipzig, Germany, pp. 279–279.
Munsell. (2000) Munsell Soil Color Charts. Gretag Macbeth, New York, USA, 9 pp.
Nixon, K.C. & Wheeler, Q.D. (1990) An amplification of the phylogenetic species concept. Cladistics, 6, 211–223.
https://doi.org/10.1111/j.1096-0031.1990.tb00541.xOrians, G.H. (1985) Blackbirds of the Americas. University of Washington, Seattle, USA, 163 pp.
Parkes, K.C. (1966) Geographic variation in Azara's Marsh Blackbird Agelaius cyanopus. Proceedings of the Biological Society of Washington, 79, 1–12.
Parkes, K.C. (1972) On some British Museum specimens of the Unicolored Blackbird Agelaius cyanopus. Bulletin of the British Ornithologist's Club, 92, 171–172.
Parrini, R., Raposo, M.A., Pacheco, J.F., Carvalhaes, A.M.P., Melo Júnior, T.A., Fonseca, P.S.M. & Minns, J. (1999) Birds of the Chapada Diamantina, Bahia, Brazil. Cotinga, 11, 86–95.
Patten, M.A. & Unitt, P. (2002) Diagnosability versus mean differences of Sage Sparrow subspecies. The Auk, 119, 26–35.
https://doi.org/10.1642/0004-8038(2002)119[0026:DVMDOS]2.0.CO;2Paynter, R.A. Jr. (1989) Ornithological Gazetteer of Paraguay, 2nd ed. Museum of Comparative Zoology, Cambridge, USA, iv + 59 pp.
https://doi.org/10.5962/bhl.title.14584Paynter, R.A. Jr. (1992) Ornithological Gazetteer of Bolivia, 2nd ed. Museum of Comparative Zoology, Cambridge, USA, vi + 185 pp.
https://doi.org/10.5962/bhl.title.14591Paynter, R.A. Jr. (1995) Ornithological Gazetteer of Argentina, 2nd ed. Museum of Comparative Zoology, Cambridge, USA, ix + 1043 pp.
https://doi.org/10.5962/bhl.title.14627Paynter, R.A. Jr. & Mayr, E. (Eds.), (1968) Check-list of Birds of the World, vol. 14. Museum of Comparative Zoology, Cambridge, USA, x + 433 pp.
Paynter, R.A. Jr. & Traylor, M.A. Jr. (1991) Ornithological Gazetteer of Brazil, 2 vols. Museum of Comparative Zoology, Cambridge, USA, vii + 788 pp.
Pearman, M. (1994) Neotropical notebook. Cotinga, 2, 26–31.
Plenge, M.A. (2015) Species and Subspecies of the Birds of Peru, Passeriformes Oscines, part 4. Published by the author, Lima, Peru.
Powell, A.F.L., Barker, F.K., Lanyon, S.M., Burns, K.J., Klicka, J. & Lovette, I.J. (2014) A comprehensive species-level molecular phylogeny of the New World blackbirds (Icteridae). Molecular Phylogenetics & Evolution, 71, 94–112.
https://doi.org/10.1016/j.ympev.2013.11.009Price, J.J. & Eaton, M.D. (2014) Reconstructing the evolution of sexual dichromatism: current color diversity does not reflect past rates of male and female change. Evolution, 68, 2026–2037.
https://doi.org/10.1111/evo.12417Proctor, N.S. & Lynch, P.J. (1993) Manual of Ornithology: Avian Structure & Function. Yale University, Yale, USA, xii + 340 pp.
Remsen, J.V. Jr. (2015) Book review: HBW and BirdLife International Illustrated Checklist of the Birds of the World Volume 1: Non-passerines. Journal of Field Ornithology, 86, 182–187.
Remsen, J.V. Jr. & Parker, T.A. III. (1983) Contribution of river-created habitats to bird species richness in Amazonia. Biotropica, 15, 223–231.
https://doi.org/10.2307/2387833Ridgely, R.S. & Tudor, G. (2009) Field Guide to the Songbirds of South America: the Passerines. University of Texas Press, Austin, USA, viii + 750 pp.
Sangster, G. (2014) The application of species criteria in avian taxonomy and its implications for the debate over species concepts. Biological Review, 89, 199–214.
https://doi.org/10.1111/brv.12051Schneider, A. & Sick, H. (1962) Sôbre a distribuição de algumas aves do sudeste do Brasil segundo coleções do Museu Nacional. Boletim do Museu Nacional, Nova Série, Zoologia, 239, 1–15.
Sclater, P.L. (1886) Catalogue of the Passeriformes, or Perching Birds, in the Collection of the British Museum, Fringilliformes, part II, vol. XI. British Museum, London, UK, 427 pp.
Snethlage, E. (1914) Catálogo das aves amazônicas, contendo todas as espécies descriptas e mencionadas até 1913. Boletim do Museu Paraense de História Natural e Ethnografia, 8, 1–530.
Snethlage, E. (1926) Resumo dos trabalhos executados na Europa, de 1924 a 1925, em museus de História Natural, principalmente no Museum Fur Naturkunde de Berlim. Boletim do Museu Nacional, 2, 35–70.
StatSoft. (2007) Statistica, version 8.0 (Computer program). StatSoft, Inc., Tulsa, USA.
Swainson, W. (1838) Animals in Menageries. Printed for Longman, Orme, Brown, Green, & Longmans, and John Taylor, London, UK, vi + 372 pp.
https://doi.org/10.5962/bhl.title.41853Tabachnick, B.G. & Fidell, L.S. (2007) Using Multivariate Statistics, 5th ed. Pearson, Boston, USA, xxviii + 980 pp.
Vanzolini, P.E. (1992) A Supplement to the Ornithological Gazetteer of Brazil. Museu de Zoologia, Universidade de São Paulo, São Paulo, Brazil, 252 pp.
Vieillot, L.J.P. (1819) Le Troupiale aux pieds bleus, Agelaius cyanopus. In: Sève, J.E. (Ed) Nouveau dictionnaire d'histoire naturelle, nouvelle édition, vol. 34. Chez Deterville, Paris, France, pp. 552–553.
von Pelzeln, A. (1868–1870) Zur Ornithologie Brasiliens: Resultate von Johann Natterers Reisen in den Jahren 1817 bis 1835, parts I–IV. Pichler's Withwe & Sohn, Vienna, Austria, LIX + 462 + 17 pp.
Webster, M.S. (1992) Sexual dimorphism, mating system and body size in New World blackbirds (Icterinae). Evolution, 46, 1621–1641.
https://doi.org/10.2307/2410020Willis, E.O. & Oniki, Y. (1991) Avifaunal transects across the open zones of northern Minas Gerais, Brazil. Ararajuba, 2, 41–58.
Willis, E.O. & Oniki, Y. (2003) Aves do Estado de São Paulo. Divisa, Rio Claro, Brazil, 400 pp.
Zar, J.H. (2010) Biostatistical Analysis, 5th ed. Prentice Hall, New Jersey, USA, xiv + 944 pp.
Zink, R.M. & Remsen, J.V. Jr. (1986) Evolutionary processes and patterns of geographic variation in birds. Current Ornithology, 4, 1–69.
zu Wied-Neuwied, M. (1831) Beiträge zur Naturgeschichte von Brasilien, vol. 3, pt. 2. Landes-Industrie-Comptoirs, Weimar, Germany, pp. 637–1277.