Plumages, Molts, and Structure

All plumages are rather poorly described, and the following is from Jaramillo and Burke (2 Jaramillo, A., and P. Burke (1999). New World Blackbirds: The Icterids. Christopher Helm, London, UK. Close ) unless noted otherwise.

Immature

Immature yuracares, presumably older individuals, are said to resemble adults, but with the chestnut on the under parts more restricted and mixed with green on the back (1 Cassin, J. (1867). A third study of the Icteridae. 3. Sub-family Icterinae. Proceedings of the National Acadamy of Science of Philadelphia 19:45–74. Close ).

Adult

The head, neck, and upper breast of the nominate subspecies are blackish brown, giving the appearance of a dark hood. The mantle, rump, thighs, and rest of the underparts are chestnut, blending smoothly on the chest and back into the black of the head and neck. The wings are black with chestnut outer edges to the primaries and secondaries, such that they appear mainly chestnut when folded. The wing-linings are chestnut-black. The tail is yellow with the central pair of rectrices (R1) entirely dark brown. These black feathers are slightly (20 mm) shorter than the longest yellow feathers, and when seen from below, the tail can appear entirely yelllow. Sexes are similar, but males have three long (90 mm) crest feathers, which may be visible in the field. Females are smaller, lack the crest feathers, and are somewhat duller in coloration (see Measurements).

Not well described. From Jaramillo and Burke (2 Jaramillo, A., and P. Burke (1999). New World Blackbirds: The Icterids. Christopher Helm, London, UK. Close ):

“Adults change their entire plumage once a year through the definitive pre-basic moult. In Amazonas, Peru, birds are moulting in July, while in Santa Cruz, Bolivia, the moult takes place in April. The definitive pre-basic moult takes place after the breeding season, therefore it is safe to say that in E Venezuela this moult takes place after April. The timing and extent of the first pre-basic moult is not known. There is no evidence for prealternate moults.”

Bill

Largely black with up to a third of the tip being described as red (neivae; 6 Snethlage, E. (1925). Neue Vogelarten aus Nord-Brasilen. Journal of Ornithology. 73(2): 264-274. Close ), reddish orange (yuracares; 7 Olivares, A. (1962). Aves de la región sur de la Sierra de La Macarena, Meta, Colombia. Rev. Acad. Colombiana Cienc.. 11(44): 305-346. Close ), vermilion (bifasciatus; 8 Hellmayr, C. E. (1912). Zoologische Ergebnisse einer Reise in das Mündungsgebiet des Amazonas Herausgegeben von Lorenz Muller. II. Vögel. Abhandlungen der Mathematisch-Physikalischen Klasse der Königlich Bayerischen Akademie der Wissenschaften 26(2):1–142 Close ), or yellow or pale yellow (yuracares; 1 Cassin, J. (1867). A third study of the Icteridae. 3. Sub-family Icterinae. Proceedings of the National Acadamy of Science of Philadelphia 19:45–74. Close , 9 Salvadori, T., and E. Festa (1899). Viaggio del Dr. Enrico Festa nell’ Ecuador. Uccelli. Parte prima – Passeres oscines. Bollettino del Musei di zoologia ed anatomia comparata della R. Università di Torino 15: 1–31. Close ). The tongue, and presumably the mouth lining is said to be pale gray (bifasciatus; 10 von Pelzeln, A. (1870). Zur Ornithologie Brasiliens: Resultate von Johann Natterers Reisen in den Jahren 1817 bis 1835. Abtheilung III [part 3]. A. Pichler's Witwe & Sohn, Vienna, Austria. Close ).

Iris

Generally reported as dark brown (1 Cassin, J. (1867). A third study of the Icteridae. 3. Sub-family Icterinae. Proceedings of the National Acadamy of Science of Philadelphia 19:45–74. Close , 11 Berlepsch, H. G. Von, and E. Hartert (1902). On the Birds of the Orinoco region. Novitates Zoologicae 9:1–135. Close , 8 Hellmayr, C. E. (1912). Zoologische Ergebnisse einer Reise in das Mündungsgebiet des Amazonas Herausgegeben von Lorenz Muller. II. Vögel. Abhandlungen der Mathematisch-Physikalischen Klasse der Königlich Bayerischen Akademie der Wissenschaften 26(2):1–142 Close ), but Snethlage (6 Snethlage, E. (1925). Neue Vogelarten aus Nord-Brasilen. Journal of Ornithology. 73(2): 264-274. Close ) describes the iris of neivae as pale gray in males and brown in females. In addition, von Tschudi (12 von Tschudi, J. J. (1844-1846). Untersuchungen über di Fauna Peruana. Druck und Verlag von Scheitlin und Zollikofer. St. Gallen, Switzerland. Close ) gives the eye color of Peruvian yuracares as whitish-blue, while Olivares (7 Olivares, A. (1962). Aves de la región sur de la Sierra de La Macarena, Meta, Colombia. Rev. Acad. Colombiana Cienc.. 11(44): 305-346. Close ) gives the eye color of yuracares in eastern Colombia as bluish. These examples suggest the possibility of eye-color change with age.

Facial Skin

Pinkish or reddish. Also described as reddish violet (bifasciatus; 8 Hellmayr, C. E. (1912). Zoologische Ergebnisse einer Reise in das Mündungsgebiet des Amazonas Herausgegeben von Lorenz Muller. II. Vögel. Abhandlungen der Mathematisch-Physikalischen Klasse der Königlich Bayerischen Akademie der Wissenschaften 26(2):1–142 Close ). Birds from the upper Orinoco Basin (yuracares) were described by von Berlepsch and Hartert (11 Berlepsch, H. G. Von, and E. Hartert (1902). On the Birds of the Orinoco region. Novitates Zoologicae 9:1–135. Close ) as having the bare facial patch orange gray near the base of the mandible, grading to red violet. In immatures, the coloration of the facial skin is paler (2 Jaramillo, A., and P. Burke (1999). New World Blackbirds: The Icterids. Christopher Helm, London, UK. Close ).

Tarsi and Toes

Black to brownish black (1 Cassin, J. (1867). A third study of the Icteridae. 3. Sub-family Icterinae. Proceedings of the National Acadamy of Science of Philadelphia 19:45–74. Close , 9 Salvadori, T., and E. Festa (1899). Viaggio del Dr. Enrico Festa nell’ Ecuador. Uccelli. Parte prima – Passeres oscines. Bollettino del Musei di zoologia ed anatomia comparata della R. Università di Torino 15: 1–31. Close , 8 Hellmayr, C. E. (1912). Zoologische Ergebnisse einer Reise in das Mündungsgebiet des Amazonas Herausgegeben von Lorenz Muller. II. Vögel. Abhandlungen der Mathematisch-Physikalischen Klasse der Königlich Bayerischen Akademie der Wissenschaften 26(2):1–142 Close , 6 Snethlage, E. (1925). Neue Vogelarten aus Nord-Brasilen. Journal of Ornithology. 73(2): 264-274. Close ).

Note: The measurements from Cassin (1 Cassin, J. (1867). A third study of the Icteridae. 3. Sub-family Icterinae. Proceedings of the National Acadamy of Science of Philadelphia 19:45–74. Close ) provided below were converted from inches.

Linear Measurements

Total Length

• yuracares: ♂♂ – c. 45.7 cm (1 Cassin, J. (1867). A third study of the Icteridae. 3. Sub-family Icterinae. Proceedings of the National Acadamy of Science of Philadelphia 19:45–74. Close ).
• yuracares: ♀♀ – c. 38.1 cm (1 Cassin, J. (1867). A third study of the Icteridae. 3. Sub-family Icterinae. Proceedings of the National Acadamy of Science of Philadelphia 19:45–74. Close ).
• bifasciatus: ♂♂ – c. 45.7-50.8 cm (1 Cassin, J. (1867). A third study of the Icteridae. 3. Sub-family Icterinae. Proceedings of the National Acadamy of Science of Philadelphia 19:45–74. Close ).
• bifasciatus: ♀♀ – c. 35.6-38.1 cm (1 Cassin, J. (1867). A third study of the Icteridae. 3. Sub-family Icterinae. Proceedings of the National Acadamy of Science of Philadelphia 19:45–74. Close ).

Wing

• yuracares: ♂♂ – 241 mm (n = ?; 1 Cassin, J. (1867). A third study of the Icteridae. 3. Sub-family Icterinae. Proceedings of the National Acadamy of Science of Philadelphia 19:45–74. Close ); 210, 270 mm (13 Taczanowski, L. (1884). Ornithologie du Pérou. Volumes 1–2. R. Friedländer und Sohn & Oberthur, Berlin, Germany. Close ); 264 mm (14 Gyldenstolpe, N. (1945). The bird fauna of Rio Jurua in Western Brazil. Kungliga Svenska Vetenskapsakademiens Handllingar Serie 3, 22(3):1–338. Close ); 231, 272 mm (14 Gyldenstolpe, N. (1945). The bird fauna of Rio Jurua in Western Brazil. Kungliga Svenska Vetenskapsakademiens Handllingar Serie 3, 22(3):1–338. Close ); mean 252.5 mm, range 226-292 mm (n = 10; 2 Jaramillo, A., and P. Burke (1999). New World Blackbirds: The Icterids. Christopher Helm, London, UK. Close ).
• yuracares: ♀♀ – 191 mm (n = ?; 1 Cassin, J. (1867). A third study of the Icteridae. 3. Sub-family Icterinae. Proceedings of the National Acadamy of Science of Philadelphia 19:45–74. Close ); 204, 208 mm (14 Gyldenstolpe, N. (1945). The bird fauna of Rio Jurua in Western Brazil. Kungliga Svenska Vetenskapsakademiens Handllingar Serie 3, 22(3):1–338. Close ); 201, 202 mm (15 Gyldenstolpe, N. (1945). A contribution to the ornithology of northern Bolivia. Kungliga Svenska Vetenskapsakademiens Handlingar 23(1):1–300. Close ); mean 207.7 mm, range 192-219 mm (n = 8; 2 Jaramillo, A., and P. Burke (1999). New World Blackbirds: The Icterids. Christopher Helm, London, UK. Close ).
• neivae: ♂♂ – 245 mm (6 Snethlage, E. (1925). Neue Vogelarten aus Nord-Brasilen. Journal of Ornithology. 73(2): 264-274. Close , 2 Jaramillo, A., and P. Burke (1999). New World Blackbirds: The Icterids. Christopher Helm, London, UK. Close ).
• neivae: ♀♀ – 194, 197 mm (6 Snethlage, E. (1925). Neue Vogelarten aus Nord-Brasilen. Journal of Ornithology. 73(2): 264-274. Close , 2 Jaramillo, A., and P. Burke (1999). New World Blackbirds: The Icterids. Christopher Helm, London, UK. Close ), 202 mm (16 Hellmayr, C. E. (1937). Catalogue of birds of the Americas, Part X. Icteridae. Field Museum of Natural History, Zoology Series, Vol. 13, Publ. 381. Close ).
• bifasciatus: ♂♂ – 241-251 mm (1 Cassin, J. (1867). A third study of the Icteridae. 3. Sub-family Icterinae. Proceedings of the National Acadamy of Science of Philadelphia 19:45–74. Close ); 165 mm (17 Hellmayr, C. E. (1906). Revision der Spix’schen Typen Brasilianischer Vögel. Abhandlungen der II. Klasse der Königlichen Bayerischen Akademie der Wissenschaften 22(3):1–163 Close ); 262 mm (2 Jaramillo, A., and P. Burke (1999). New World Blackbirds: The Icterids. Christopher Helm, London, UK. Close ).
• bifasciatus: ♀♀ – 203 mm (1 Cassin, J. (1867). A third study of the Icteridae. 3. Sub-family Icterinae. Proceedings of the National Acadamy of Science of Philadelphia 19:45–74. Close ); 255 mm (8 Hellmayr, C. E. (1912). Zoologische Ergebnisse einer Reise in das Mündungsgebiet des Amazonas Herausgegeben von Lorenz Muller. II. Vögel. Abhandlungen der Mathematisch-Physikalischen Klasse der Königlich Bayerischen Akademie der Wissenschaften 26(2):1–142 Close ); mean 202 mm, range 193-208 mm (n = 3; 2 Jaramillo, A., and P. Burke (1999). New World Blackbirds: The Icterids. Christopher Helm, London, UK. Close ).

Tail

• yuracares: ♂♂ – 191 mm (n = ?; 1 Cassin, J. (1867). A third study of the Icteridae. 3. Sub-family Icterinae. Proceedings of the National Acadamy of Science of Philadelphia 19:45–74. Close ); 165, 210 mm (13 Taczanowski, L. (1884). Ornithologie du Pérou. Volumes 1–2. R. Friedländer und Sohn & Oberthur, Berlin, Germany. Close ); 199 mm (14 Gyldenstolpe, N. (1945). The bird fauna of Rio Jurua in Western Brazil. Kungliga Svenska Vetenskapsakademiens Handllingar Serie 3, 22(3):1–338. Close ); 167, 194 mm (15 Gyldenstolpe, N. (1945). A contribution to the ornithology of northern Bolivia. Kungliga Svenska Vetenskapsakademiens Handlingar 23(1):1–300. Close ); mean 200.1 mm, range 182-246 mm (n = 10; 2 Jaramillo, A., and P. Burke (1999). New World Blackbirds: The Icterids. Christopher Helm, London, UK. Close ).
• yuracares: ♀♀ – 165-178 mm (n = ?; 1 Cassin, J. (1867). A third study of the Icteridae. 3. Sub-family Icterinae. Proceedings of the National Acadamy of Science of Philadelphia 19:45–74. Close ); 154, 158 mm (14 Gyldenstolpe, N. (1945). The bird fauna of Rio Jurua in Western Brazil. Kungliga Svenska Vetenskapsakademiens Handllingar Serie 3, 22(3):1–338. Close ); 153, 151 mm (15 Gyldenstolpe, N. (1945). A contribution to the ornithology of northern Bolivia. Kungliga Svenska Vetenskapsakademiens Handlingar 23(1):1–300. Close ); mean 167.4 mm, range 154-183 mm (n = 8; 2 Jaramillo, A., and P. Burke (1999). New World Blackbirds: The Icterids. Christopher Helm, London, UK. Close ).
• neivae: ♀♀ – 155 mm (16 Hellmayr, C. E. (1937). Catalogue of birds of the Americas, Part X. Icteridae. Field Museum of Natural History, Zoology Series, Vol. 13, Publ. 381. Close ).
• bifasciatus: ♂♂ – 203 mm (1 Cassin, J. (1867). A third study of the Icteridae. 3. Sub-family Icterinae. Proceedings of the National Acadamy of Science of Philadelphia 19:45–74. Close ); 202 mm (17 Hellmayr, C. E. (1906). Revision der Spix’schen Typen Brasilianischer Vögel. Abhandlungen der II. Klasse der Königlichen Bayerischen Akademie der Wissenschaften 22(3):1–163 Close ); 210 mm (2 Jaramillo, A., and P. Burke (1999). New World Blackbirds: The Icterids. Christopher Helm, London, UK. Close ).
• bifasciatus: ♀♀ – 152-165 mm (1 Cassin, J. (1867). A third study of the Icteridae. 3. Sub-family Icterinae. Proceedings of the National Acadamy of Science of Philadelphia 19:45–74. Close ); 190 mm (8 Hellmayr, C. E. (1912). Zoologische Ergebnisse einer Reise in das Mündungsgebiet des Amazonas Herausgegeben von Lorenz Muller. II. Vögel. Abhandlungen der Mathematisch-Physikalischen Klasse der Königlich Bayerischen Akademie der Wissenschaften 26(2):1–142 Close ); mean 155 mm, range 140-170 mm (n = 3; 2 Jaramillo, A., and P. Burke (1999). New World Blackbirds: The Icterids. Christopher Helm, London, UK. Close ).

Bill (culmen)

• yuracares: ♂♂ – 80 mm (14 Gyldenstolpe, N. (1945). The bird fauna of Rio Jurua in Western Brazil. Kungliga Svenska Vetenskapsakademiens Handllingar Serie 3, 22(3):1–338. Close ); 65, 75 mm (15 Gyldenstolpe, N. (1945). A contribution to the ornithology of northern Bolivia. Kungliga Svenska Vetenskapsakademiens Handlingar 23(1):1–300. Close ); mean 78.7 mm, range 73-83 mm (n = 10; 2 Jaramillo, A., and P. Burke (1999). New World Blackbirds: The Icterids. Christopher Helm, London, UK. Close ).
• yuracares: ♀♀ – 60, 63 mm (14 Gyldenstolpe, N. (1945). The bird fauna of Rio Jurua in Western Brazil. Kungliga Svenska Vetenskapsakademiens Handllingar Serie 3, 22(3):1–338. Close ); 60, 58 mm (15 Gyldenstolpe, N. (1945). A contribution to the ornithology of northern Bolivia. Kungliga Svenska Vetenskapsakademiens Handlingar 23(1):1–300. Close ); mean 60.9 mm, range 58-63 mm (n = 7; 2 Jaramillo, A., and P. Burke (1999). New World Blackbirds: The Icterids. Christopher Helm, London, UK. Close ).
• neivae: ♂♂ – 65 mm (6 Snethlage, E. (1925). Neue Vogelarten aus Nord-Brasilen. Journal of Ornithology. 73(2): 264-274. Close , 2 Jaramillo, A., and P. Burke (1999). New World Blackbirds: The Icterids. Christopher Helm, London, UK. Close ).
• neivae: ♀♀ – 52, 54 mm (6 Snethlage, E. (1925). Neue Vogelarten aus Nord-Brasilen. Journal of Ornithology. 73(2): 264-274. Close , 2 Jaramillo, A., and P. Burke (1999). New World Blackbirds: The Icterids. Christopher Helm, London, UK. Close ), 54.5 mm (16 Hellmayr, C. E. (1937). Catalogue of birds of the Americas, Part X. Icteridae. Field Museum of Natural History, Zoology Series, Vol. 13, Publ. 381. Close ).
• bifasciatus: ♂♂ – 69.5 mm (17 Hellmayr, C. E. (1906). Revision der Spix’schen Typen Brasilianischer Vögel. Abhandlungen der II. Klasse der Königlichen Bayerischen Akademie der Wissenschaften 22(3):1–163 Close ); 72 mm (2 Jaramillo, A., and P. Burke (1999). New World Blackbirds: The Icterids. Christopher Helm, London, UK. Close ).
• bifasciatus: ♀♀ – 68.5 mm (8 Hellmayr, C. E. (1912). Zoologische Ergebnisse einer Reise in das Mündungsgebiet des Amazonas Herausgegeben von Lorenz Muller. II. Vögel. Abhandlungen der Mathematisch-Physikalischen Klasse der Königlich Bayerischen Akademie der Wissenschaften 26(2):1–142 Close ); mean 54.0 mm, range 53-55 mm (n = 3; 2 Jaramillo, A., and P. Burke (1999). New World Blackbirds: The Icterids. Christopher Helm, London, UK. Close ).

Tarsus

• yuracares: ♂♂ – 50, 60 mm (13 Taczanowski, L. (1884). Ornithologie du Pérou. Volumes 1–2. R. Friedländer und Sohn & Oberthur, Berlin, Germany. Close ); 55 mm (14 Gyldenstolpe, N. (1945). The bird fauna of Rio Jurua in Western Brazil. Kungliga Svenska Vetenskapsakademiens Handllingar Serie 3, 22(3):1–338. Close ); 53, 52 mm (15 Gyldenstolpe, N. (1945). A contribution to the ornithology of northern Bolivia. Kungliga Svenska Vetenskapsakademiens Handlingar 23(1):1–300. Close ); mean 57.5 mm, range 55-60 mm (n = 10; 2 Jaramillo, A., and P. Burke (1999). New World Blackbirds: The Icterids. Christopher Helm, London, UK. Close ).
• yuracares: ♀♀ – 43, 43 mm (14 Gyldenstolpe, N. (1945). The bird fauna of Rio Jurua in Western Brazil. Kungliga Svenska Vetenskapsakademiens Handllingar Serie 3, 22(3):1–338. Close ); 42, 41 mm (15 Gyldenstolpe, N. (1945). A contribution to the ornithology of northern Bolivia. Kungliga Svenska Vetenskapsakademiens Handlingar 23(1):1–300. Close ); mean 46.8 mm, range 42-50 mm (n = 8; 2 Jaramillo, A., and P. Burke (1999). New World Blackbirds: The Icterids. Christopher Helm, London, UK. Close ).
• neivae: ♂♂ – 52 mm (6 Snethlage, E. (1925). Neue Vogelarten aus Nord-Brasilen. Journal of Ornithology. 73(2): 264-274. Close , 2 Jaramillo, A., and P. Burke (1999). New World Blackbirds: The Icterids. Christopher Helm, London, UK. Close ).
• neivae: ♀♀ – 41, 42 mm (6 Snethlage, E. (1925). Neue Vogelarten aus Nord-Brasilen. Journal of Ornithology. 73(2): 264-274. Close , 2 Jaramillo, A., and P. Burke (1999). New World Blackbirds: The Icterids. Christopher Helm, London, UK. Close ).
• bifasciatus: ♂♂ – 47 mm (2 Jaramillo, A., and P. Burke (1999). New World Blackbirds: The Icterids. Christopher Helm, London, UK. Close ).
• bifasciatus: ♀♀ – mean 43.7 mm, range 40-46 mm (n = 3; 2 Jaramillo, A., and P. Burke (1999). New World Blackbirds: The Icterids. Christopher Helm, London, UK. Close ).

Mass

• yuracares: ♂♂ – 430 g (n = 1; 18 Bates, J. M., M. C. Garvin, D. C. Schmitt and C. G. Schmitt. (1989). Notes on Bird Distribution in northeastern Dpto. Santa Cruz, Bolivia, with 15 species new to Bolivia. Bulletin of the British Ornithologists' Club 109:236-244. Close ); mean 457.8 ± 39.1 g (n = 6; 5 Fraga, R.M. and Kreft, S. (2007). Natural history and breeding behavior of the Olive (Psarocolius yuracares) and Yellow-billed (P. angustifrons alfredi) Oropendolas in the Chapare province, Bolivia. Orn. Neotropical 18(2): 251–261. Close ).
• yuracares: ♀♀ – mean 250.5 g ± 7.8 g (n = 4; 5 Fraga, R.M. and Kreft, S. (2007). Natural history and breeding behavior of the Olive (Psarocolius yuracares) and Yellow-billed (P. angustifrons alfredi) Oropendolas in the Chapare province, Bolivia. Orn. Neotropical 18(2): 251–261. Close ).
• yuracares: sex not specified – 360 g (n = ?; 19 Terborgh, J., S. K. Robinson, T. A. Parker, C. A. Munn, and N. Pierpont (1990). Structure and organization of an Amazonian forest bird community. Ecological Monographs 60(2):213–238. Close ).
• neivae: ♂♂ – 290, 385, 445 g (20 Graves, G. R., and R. L. Zusi. (1990). Avian body weights from the lower Rio Xingu, Brazil. Bulletin of the British Ornithologists' Club 110:20-25. Close ).
• neivae: ♀♀ – 184, 210, 215 g (20 Graves, G. R., and R. L. Zusi. (1990). Avian body weights from the lower Rio Xingu, Brazil. Bulletin of the British Ornithologists' Club 110:20-25. Close ).