New World Blackbirds (Icteridae)

Russet-backed Oropendola (Psarocolius angustifrons) - HBW 16, p. 753

French: Cassique roussâtre German: Breithauben-Stirnvogel Spanish: Cacique Dorsirrufo
Other common names: Russet Oropendola; Black-billed Oropendola (angustifrons); Yellow-billed Oropendola (Andean races combined); Alfred’s/Pale-billed Oropendola (alfredi); Oleaginous Oropendola (oleagineus); Olive-bellied Oropendola (neglectus)

Taxonomy: Cassicus angustifrons Spix, 1824, São Paulo de Olivença, south bank of upper River Solimões, west Amazonas, Brazil.
Taxonomy complex and confusing. Nominate race has blackish bill; the other six races, with yellow bill, may represent a distinct species. Recent fieldwork in foothills of Colombian E Andes revealed that race neglectus does not associate with nominate, the two behaving as separate species, and this supported by DNA studies indicating considerable sequence divergence between the four N Andean forms (Venezuela S to Ecuador) and nominate race; also, songs of some of N Andean races are distinctive. On other hand, DNA divergence between alfredi and nominate was relatively small, and songs of the two are similar, suggesting that they are conspecific (also, intermediate specimens reported from E Ecuador). Analyses of mitochondrial DNA indicate considerable divergence between some montane populations, which may deserve full species status, but a more detailed analysis of the full complex is needed. Proposed race australis (described from Santa Cruz, in C Bolivia) supposedly darker than alfredi, but considered to fall within range of variation of latter and therefore synonymized with it. Seven subspecies currently recognized.

Subspecies and Distribution:

oleagineus (P. L. Sclater, 1883) - mountains and foothills of coastal N Venezuela (from Carabobo E to Miranda).
neglectus (Chapman, 1914) - Sierra de Perijá (Colombia–Venezuela border); W Andes of Venezuela and E slope of E cordillera in Colombia (S to Caquetá).
salmoni (P. L. Sclater, 1883) - W & C Andes of Colombia (S to Nariño).

See all 7 subspecies

oleagineus (P. L. Sclater, 1883) - mountains and foothills of coastal N Venezuela (from Carabobo E to Miranda).
neglectus (Chapman, 1914) - Sierra de Perijá (Colombia–Venezuela border); W Andes of Venezuela and E slope of E cordillera in Colombia (S to Caquetá).
salmoni (P. L. Sclater, 1883) - W & C Andes of Colombia (S to Nariño).
sincipitalis (Cabanis, 1873) - W slope of E Andes of Colombia (from Santander S to upper Magdalena Valley).
atrocastaneus (Cabanis, 1873) - W slope in Ecuador.
alfredi (Des Murs, 1856) - E Andean slopes and foothills from SE Ecuador (Morona Santiago) S to Peru and C Bolivia (Cochabamba and Santa Cruz).
angustifrons (Spix, 1824) - low E Andean foothills from S Colombia (S from Meta and Vaupés) S to E Ecuador and NE Peru (Loreto and N Ucayali) and W Brazil (Amazonian lowlands E to lower R Purús).