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Number of species: 72

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Yellow-bellied Flycatcher - Empidonax flaviventris

Yellow-bellied Flycatcher undergoes a partial preformative molt and incomplete first prealternate molt, resulting in distinct molt limits among the median or greater coverts (fall) or among the primaries and secondaries (spring); older individuals show more subtle differences in the wing. SY and ASY birds can usually be distinguished as late as August or September. Sexes are identical in plumage; breeding females have a brood patch, but males have a poorly developed cloacal protuberance and may be more difficult to identify with confidence.

Yellow-bellied Flycatcher is similar in appearance to several other Empidonax flycatchers, most notably Acadian, Cordilleran, and Pacific-slope. Note the yellowish and rounded eye-ring and combination of uniform and distinctly green upperparts and yellowish throughout the underparts.

Quick Tips:

  • Examine the primaries and secondaries for evidence of an eccentric molt, which is absent in HY birds, but typically present to some degree in all older age classes.
  • Check the shape and condition of the rectrices. They are narrow and pointed on HY birds, vs. broad and rounded for all older age classes. However, the feathers are more worn on ASY individuals than SY.
  • Look for a distinct molt limit among the greater coverts or between the greater and primary coverts, which is indicative of HY/SY individuals.

Species account prepared by McGill Bird Observatory

Click on any image below to bring up the side-by-side comparison tool.
Age / Sex  Image sets 
Hatch year / Unknown
Molt limit among median or greater coverts, with replaced greater coverts darker and with yellowish to white tips, compared to retained outer greater coverts with buffy tips; rectrices narrow and pointed.
Thumbnail - LL4-2400-08231-Empidonax_flaviventris_AOU_7_52-1285.jpg Thumbnail - LL4-2400-08231-Empidonax_flaviventris_AOU_7_52-1286.jpg Thumbnail - LL4-2400-08231-Empidonax_flaviventris_AOU_7_52-1287.jpg

Thumbnail - LL4-2400-08317-Empidonax_flaviventris_AOU_7_52-1316.jpg Thumbnail - LL4-2400-08317-Empidonax_flaviventris_AOU_7_52-1318.jpg Thumbnail - LL4-2400-08317-Empidonax_flaviventris_AOU_7_52-1319.jpg Thumbnail - LL4-2400-08317-Empidonax_flaviventris_AOU_7_52-1317.jpg
Second year / Unknown
Molt limits on the wing between faded juvenile primary coverts and central primaries and secondaries vs. darker fresher feathers on the rest of the wing; rectrices broad, rounded, and fresh.
Thumbnail - MH3-NA_332-Empidonax_flaviventris_AOU_7_52-771.jpg
After second year / Unknown
Slight contrasts on the wing between somewhat worn basic feathers, and slightly darker and fresher alternate plumage, usually among the inner greater coverts and tertials, as well as within the primaries and secondaries; rectrices broad and rounded but rel
Thumbnail - MH3-NA_330-Empidonax_flaviventris_AOU_7_52-769.jpg

Thumbnail - MH3-NA_331-Empidonax_flaviventris_AOU_7_52-770.jpg

Additional age / sex class descriptions

The following additional age / sex class descriptions were found for this species:
Age / Sex   Age / Sex class description
Juvenile / Unknown Upperparts brownish, with buffy wing bars; rectrices narrow and pointed.
After hatch year / Unknown Wing relatively uniform in appearance, either faded and worn (prior to migration) or dark and fresh (after migration), but possibly showing some contrast among retained and replaced primaries and secondaries in both cases; rectrices relatively broad and ro
Number of species: 72

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