The Yellow-margined Flatbill or Yellow-margined Flycatcher (Tolmomyias assimilis) is a species of bird in the Tyrannidae family. It is found in humid forest in southern Central America, and the Chocó and Amazon in South America.
There are significant differences (notably voice) between the populations east and west of the Andes, leading to suggestions that the two should be regarded as separate species, in which case the population west of the Andes retains the English name Yellow-margined Flatbill (or Flycatcher) but with the scientific name T. flavotectus, while the Amazonian population retains the scientific name T. assimilis but with the English name Zimmer’s Flatbill (or Flycatcher).
Both population closely resemble the Yellow-olive Flatbill, and are typically best separated from that species by voice.
- Gill, F., Wright, M. and Donsker, D. (2009). IOC World Bird Names (version 2.2). Available at https://www.worldbirdnames.org/ Accessed 30 August 2009
- BirdLife International 2004. . 2006 IUCN Red List of Threatened Species. Downloaded on 27 July 2007.