Family Tyrant-flycatchers (Tyrannidae)

Least Concern

Western Olivaceous Flatbill (Rhynchocyclus aequinoctialis)


French: Tyranneau du Napo German: Westamazonien-Breitschnabeltyrann Spanish: Picoplano equinoccial

Cyclorhynchus æquinoctialis

P. L. Sclater

, 1858,

Río Napo, Ecuador


Hitherto treated as conspecific with R. olivaceus, but differs strongly in its song#R, a series of typically 5–10 whistles, initially flat and burry (3), gradually shifting to louder purer whistles which accelerate and rise in pitch (3), vs a fast series of very buzzy notes which descend in pitch; brighter yellow fringes on the flight-feathers and yellowish vs ochreish greater wing-coverts (1); greater amount of pale yellow on the belly, extending marginally further up to the mid-breast (1). Recording from W Amazonia might represent an intergrade between the two song types; study needed in this area. Six subspecies recognized.

What do (1) and (2) mean? Learn more about the scoring system.
Subspecies and Distribution
  • R. a. bardus (Bangs & Barbour, 1922) – E Panama and NW Colombia (N Chocó E to S Bolívar).
  • R. a. mirus Meyer de Schauensee, 1950 – NW Colombia (lower Atrato Valley and inland from coast).
  • R. a. flavus (Chapman, 1914) – N & C Colombia (Santa Marta and Magdalena to W Meta) and N Venezuela (E to Aragua and W Apure).
  • R. a. jelambianus Aveledo & Pérez, 1994 – NE Venezuela (Sucre, N Monagas).
  • R. a. tamborensis Todd, 1952 – R Lebrija (Santander), in C Colombia.
  • R. a. aequinoctialis (P. L. Sclater, 1858) – SC & SE Colombia (Meta S to Putumayo and Amazonas), E Ecuador, E Peru, W Brazil S of Amazon (E to R Madeira) and NC Bolivia (S to Cochabamba).
  • Descriptive notes

    13·5–15 cm; 14–24·5 g. Large-headed, dark olive flatbill with white eyering surrounding large dark eye. Head and upperparts dark olive, wings dusky, wing-coverts and... read more


    Song (E Peru), mainly heard at dawn, a rising series of high-pitched, squeaky whistles that... read more


    Favours dense understorey and midstorey, including areas with bamboo at least in parts of range, of... read more

    Food and feeding

    Insects recorded in stomach contents. Occurs singly or in pairs, alone or (regularly) with mixed-species flocks, perches very erect and... read more


    Birds in breeding condition in Feb–Jun in N Colombia, and Feb in NC Venezuela; nest with small young in mid Apr and another active in mid... read more


    Probably resident throughout range.

    Status and conservation

    Not globally threatened (Least Concern). Uncommon to fairly common in most of range; rare to locally uncommon in Ecuador and Colombia, where apparently absent from some areas... read more

    Recommended citation

    del Hoyo, J., Collar, N. & Kirwan, G.M. (2019). Western Olivaceous Flatbill (Rhynchocyclus aequinoctialis). 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 7 December 2019).