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Number of species: 72

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Swainson's Thrush - Catharus ustulatus

Swainson's Thrush can generally be aged by a combination of molt limits and feather condition. HY/SY individuals can be recognized by retained juvenile greater coverts with pale shafts or tips, but note that these tend to be less distinct than on other Catharus species and can fade over time, therefore some intermediates may be difficult to assess by spring. Sex is reliably determined only via brood patch / cloacal protuberance during the breeding season.

Swainson's Thrush can generally be distinguished from the other Catharus thrushes by its buffy eye ring and cheek, and its uniformaly olive-brown back and tail.

Quick Tips:

  • Look at the greater coverts - on HY/SY birds, the innermost two are generally longer, while the remainder are retained juvenile feathers and often show buffy-white shaft streaks. However, the absence of such streaks is not a reliable indicator of AHY/ASY, as some HY/SY birds may lack these markings
  • Consider the shape of the rectrices - they are narrow and relatively pointed on HY/SY birds, but broad and relatively rounded on AHY/ASY birds
  • Examine the outermost primary (p10) - on HY/SY birds it is broad, rounded and 1 mm longer to 6 mm shorter than the primary coverts, while on AHY/ASY birds it is narrow, pointed, and 4-9 mm shorter than the primary coverts

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 
After hatch year / Unknown
Wing uniform in appearance; outermost primary (p10) narrow, pointed, short; rectrices broad and rounded
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Second year / Unknown
Inner 1-5 (often 2) greater coverts usually longer than others, while remainder may have pale shaft streaks; p10 relatively broad, rounded, long; rectrices narrow and pointed
Thumbnail - MH3-NA_318-Catharus_ustulatus_AOU_7_52-754.jpg

Thumbnail - MH3-NA_376-Catharus_ustulatus_AOU_7_52-844.jpg Thumbnail - MH3-NA_376-Catharus_ustulatus_AOU_7_52-843.jpg

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Thumbnail - MH3-NA_441-Catharus_ustulatus_AOU_7_52-935.jpg
After second year / Unknown
Wing uniform in appearance; outermost primary (p10) narrow, pointed, short; rectrices broad and rounded
Thumbnail - MH3-NA_373-Catharus_ustulatus_AOU_7_52-840.jpg

Thumbnail - MH3-NA_374-Catharus_ustulatus_AOU_7_52-841.jpg

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Thumbnail - MH3-NA_491-Catharus_ustulatus_AOU_7_52-1000.jpg

Additional age / sex class descriptions

The following additional age / sex class descriptions were found for this species:
Age / Sex   Age / Sex class description
Hatch year / Unknown Inner 1-5 (often 2) greater coverts usually longer than others, while remainder may have pale shaft streaks; p10 relatively broad, rounded, long; rectrices narrow and pointed
Juvenile / Unknown Distinct pale spotting on the head, back, and wings
Number of species: 72

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