Answer:
Obviously, these birds are NOT singing during the non-breeding season, but you do often hear loud chip or call notes where Audubon’s and Myrtle Yellow-Rumped Warbler patrol during the non-breeding season.
In many cases you can hear how the Myrtle (one of the subspecies of the Yellow-rumped Warbler species) has a flatter and softer chip note than the Auduon’s.
The “ch” component of the call note is weaker for the Myrtle and it often gives many calls in rapid succession.
However, be careful. Intergrades (individuals that display visual characteristics specific to both Audubon’s and Myrtle) may announce call notes of the other subspecies. In other words, it’s possible to see a bird that looks like an Audubon’s, but it’s call note sounds like a Myrtle. This individual could likely be an intergrade.
8 comments:
I hear both in the Livermore (CA) area durig the winter.
Gloria F.
Note that there are clear plumage differences visible in most individuals, too, particularly in the pattern of the head.
r
Thanks Warbler Guy.....I'll listen more carefully.
Chuck W.
Thanks for this blog essay. interesting.
Joseph P.,
South Bend, IN
You've got great ears if you can hear the difference.
Leslie L.
You've got great ears if you can hear the difference.
Leslie L.
Do either subsp. have different feeding niches to hang out together? I 've always wondered.....
Jody Sears
Dubuque, Iowa
I cannot tell. Too hard!
Seth W.
Chicago, IL
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