Monday, October 26, 2009
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Answer by Tony Leukering
The broken eye ring on an otherwise pretty plain face, strong wing bars, side and flank streaking, and grayish tail do a good job at narrowing our quiz bird's ID to a small set of warbler species. The drabness of the underparts with the dark streaking set on off-white feathers and lacking any obvious bright yellow should take us to the duller individuals among Cape May, Yellow-rumped, and Kirtland's warblers. The second-most common species guessed, Pine Warbler, doesn't make the cut as the dull end individuals can be this dull, but those individuals also lack or nearly lack side and flank streaking.
Getting a peek at our bird's rump could help, as it would rule out Kirtland's if not gray and provide our answer if it was, as both the other two species still in consideration have yellow or yellowish rumps. But, that body part is hidden behind the folded wingtips -- what color we can see proximal from the tail base is the gray uppertail coverts. However, we can rule out Kirtland's, as our bird's undertail coverts are just too drab; Kirtland's always sport bright white there.
Separating the dull ends of the plumage spectrum of Cape May and Yellow-rumped warblers can be a bit tricky. But, our quiz bird's side/flank streaking is too prominent and Cape May also should have greenish uppertail coverts. Now that we've decided that our bird is a Yellow-rumped Warbler, it might be a good time to point out the diagnostic bit of buff-yellow on the side. Also, it would behoove us to at least attempt determining to which subspecies group of Yellow-rumped Warbler the bird belongs. The very dull head might suggest Audubon's, but the bird shows just a bit of a pale ear surround that would rule that subspecies group out. Of somewhat less utility, but still a feature to consider in this endeavor, is the distinctness and contrastiness of the eye ring, with that shown by the quiz bird being more typical of Myrtle Warbler than of Audubon's Warbler. I provide, below, another picture of this Myrtle Warbler, one in which the namesake feature is obvious, that I photographed off Delaware 11 October 2009.
One respondent's answer included a guess at the subspecies as part of the ganswer and due to the incorrectness of the subspecies guessed, the answer was precluded from being correct for the competition. I guess this is a good time to remind all that you are more than welcome to provide thoughts on subspecies, color morph, age, sex, whatever, but do not make those comments integral to your answer concerning the species presented. Another respondent getting the quiz correct provided an incorrect assessment of subspecies, too, but, as you can see below, that person separated the species answer from all other aspects:
"Yellow-rumped Warbler ("Audubon's" Warbler, fall plumage)."
Incorrect species provided as answers:
Hammond's Flycatcher - 1
Pine Warbler - 4
Cape May Warbler - 1
The 18 of 24 providing the correct answer:
Answer: Yellow-rumped Warbler ("Myrtle" Warbler)