Monday, October 11, 2010

Quiz #369 (2010-4-02) Solution

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Answer by Tony Leukering

We've got an obviously small bird (compare to leaf sizes) with a lot of distinct field marks, what with flank streaks, wing bars, tail spots, back streaking, interesting crown pattern, yellow superciliary, and, of course, braces. Despite this, interestingly, even many of the correct respondents seemed to have trouble with the quiz subject. As I've mentioned many times in this and other venues, I believe that one-field-mark identifications are anathema. However, the experienced and skilled birders often use single field marks to ID birds, that is, once they've got them assigned to some smaller group.

With the plethora of the specific field marks exhibited by our quiz bird, we really have no reason to find ourselves anywhere but among the warblers; ah, the New World warblers. We can eliminate all the non-blackish-streaked and/or non-wing-barred species, leaving us with a manageable handful: Magnolia, Cape May, Yellow-rumped, Kirtland's, Prairie, Yellow-throated, Blackburnian, Cerulean, Golden-cheeked, Black-throated Green, Black-throated Gray, Golden-cheeked, and Townsend's. Our bird's strong yellowish super eliminates most of the lot, leaving the final seven from that list. At this point, that single superb field mark comes into play, the braces.

For those that don't know the term, 'braces,' it is a British term for contrastingly pale (usually whitish) streaks on the sides of the back. Our quiz bird sports them, the other six remaining candidates lack them. In fact, we could have short-stopped the process once we knew we were among the warblers, as this species is the only ABA-area parulid that exhibits braces. However, by using the crown pattern and distinctly dark back, we could have gotten to the same place.

I took this picture of an immature Blackburnian Warbler at Cape May Point, Cape May Co., NJ, on 10 September 2010.

Incorrect species provided as answers:
Cape May Warbler - 1
Townsend's Warbler - 2
American Goldfinch - 1
Blackpoll Warbler - 1

Congratulations to the 21 of 26 getting the quiz correct:
Tyler Bell
Su Snyder
Robert McNab
George Cresswell
Margaret Smith
JoAnn Andrews
Chuck Carlson
Thomas Hall
Richard Jeffers
Margie Joy
Brandon Percival
Al Guarente
Nick Komar
Peter Wilkinson
Pam Myers
Tom Takano
Adrian Hinkle
Ben Coulter
Joel Such
Marcel Such
Chishun Kwong

Answer: Blackburnian Warbler