The yellow-olive flatbill or yellow-olive flycatcher (Tolmomyias sulphurescens) is a species of bird in the family Tyrannidae, the tyrant flycatchers. It is found in Mexico, in every Central American country, on Trinidad, and in every mainland South American country except Chile.
Taxonomy and systematics
The yellow-olive flatbill has these 16 subspecies:
T. s. cinereiceps (Sclater, PL, 1859)
T. s. flavoolivaceus (Lawrence, 1863)
T. s. berlepschi (Hartert, EJO & Goodson, 1917)
T. s. exortivus (Bangs, 1908)
T. s. asemus (Bangs, 1910)
T. s. confusus Zimmer, JT, 1939
T. s. duidae Zimmer, JT, 1939
T. s. aequatorialis (Berlepsch & Taczanowski, 1884)
T. s. cherriei (Hartert, EJO & Goodson, 1917)
T. s. peruvianus (Taczanowski, 1875)
T. s. insignis Zimmer, JT, 1939
T. s. mixtus Zimmer, JT, 1939
T. s. inornatus Zimmer, JT, 1939
T. s. pallescens (Hartert, EJO & Goodson, 1917)
T. s. grisescens (Chubb, C, 1910)
T. s. sulphurescens (Spix, 1825)
Since the late twentieth century several authors have suggested that what is now considered a single species is actually several species, perhaps as many as 12. In particular, subspecies T. s. cinereiceps and T. s. flavoolivaceus are suggested as species, and they do not appear to be the closest relatives of the other 14 subspecies. Some authors consider several of the South American subspecies to be "dubious".
