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".
Turrialba, Costa Rica
Description
The yellow-olive flatbill is 12.5 to 14 cm (4.9 to 5.5 in) long and weighs 14.5 to 15.2 g (0.51 to 0.54 oz). The sexes have the same plumage. Adults of the nominate subspecies T. s. sulphurescens have a dark olive crown and nape, a thin white band above the lores, a thin white eye-ring, and pale olive ear coverts with a dusky patch at their rear. Their upperparts are olive-green. Their wings are dusky or blackish with yellowish-olive edges on the wing coverts that form two wing bars. Their remiges have yellowish edges. Their tail is brownish to dusky with buffy edges on the...
