Quiz #413 (2011-3-08) Solution

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Solution by Bryan Guarente and Tony Leukering

I am quite pleased with the responses this week, as at least three included mention of the field mark that this quiz photo was attempting to point out. This week's quiz bird, with its extensive black on chin, throat, and upper breast; bright yellow face; and distinct black streaking on the sides should take us straight to the Parulidae. This combo of characters should also tell us that the bird is in alternate plumage and must be a male. From there, I will let Bryan Guarente's words take us down the ID track for a bit.

"The possibilities are Black-throated Green, Townsend's, and Golden-cheeked warblers. Where to go from here? I initially went to the face as lots of birders do and there noted a thin, black eyeline. That feature cuts out Townsend's Warbler, which has a more extensively black face. However, we don't even need to do that, as we can head toward the other end of the bird for our answer. Most warblers can be identified by looking at the tail area. In this case, the vent, the feathers around the part that would vent any gases. (I don't get to use that joke very often, so I had take advantage of the opportunity.) These feathers are tinged yellow, which clinches the ID: Black-throated Green Warbler is the only one of the warblers in our list that sports this characteristic."

Bryan is correct about the yellow vent strap in Black-throated Green Warbler, an excellent field character in all post-juvenal plumages of the species, and one that even many experienced birders don't know. Other characters that rule out the other species of the virens complex species include the bit of yellow below the bib (rules out Golden-cheeked and Hermit warblers), the streaking on the sides is much too extensive for Hermit Warbler, and the lack of dark streaking on the undertail coverts rules out Townsen's Warbler. Note that this individual is readily identified with multiple characters south of the legs.

I took this picture of an adult male Black-throated Green Warbler at the recently renamed Cox Hall Creek WMA (formerly Villas WMA), Cape May Co., NJ, on 1 May 2011.

Incorrect species provided as answers:
Golden-cheeked Warbler - 1

Congratulations to the 18 of 19 getting the quiz correct:
Thomas Hall
Dave Elwonger
Chuck Carlson
Kirk Huffstater
George Cresswell
Burke Angstman
Tyler Bell
Margie Joy
Robert McNab
Pam Myers
Al Guarente
Chishun Kwong
Diane Porter
Su Snyder
Christopher Hinkle
Peter Wilkinson
Marcel Such
Bryan Guarente

Answer: Black-throated Green Warbler

Quiz #412 (2011-3-07) Solution

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Solution by Tony Leukering

Once again I neglected to put in the intended caveat with a quiz picture, so I suspect that one of the five birds present scared some number of people away from responding to the quiz. Four of the birds were apparently thought to be quite easy, as no respondent missed them, what with the obvious black on the bellies and the bright bubble-gum-pink legs. However, three respondents neglected the second hyphen in "Black-bellied Whistling-Duck," so their answers were precluded from being correct for the competition.

I received answers claiming that fifth bird as Gadwall, Mallard, Mottled Duck, Northern Shoveler, Cinnamon Teal, and Blue-winged Teal, though a number of respondents did not even try (or, perhaps, did not think it a different species). However, I had intended to provide the caveat that respondents need not attempt ID of the bird lacking bright pink legs, but that bonus points would be awarded for its correct ID with no penalty for incorrect answers. Though I forgot it, I scored things as if I hadn't, giving one bonus point for the one respondent getting the ID to the wrong one of a tricky species pair (particularly tricky given this view) and two bonus points for the correct answer, because I didn't really see much in the way of definitive features to separate the two species here.

On the tricky bird, the belly is just too pale to be one of the dark Mallard-like dabblers and lacks a white tail, so Mallard and Northern Shoveler are eliminated from consideration. As the bird is noticeably smaller than the whistling-ducks, that, too, would rule out the Mallards and Mallard-like species and provide at least one strike against Gadwall, wigeons, and Northern Pintail. The extensive spotting on the belly provides the other two strikes against the wigeons and another strike each against Gadwall and Northern Pintail. The pattern on the flank feathers sends both Gadwall and Northern Pintail back to the dugout, as both species have more complex patterns there. Just to add insult to striking out, the quiz bird's squarish tail is a fourth strike and the leg color a fifth strike against an ID of Northern Pintail, which has a pointed tail and dark legs.

The bird lacks the distinctive pale wedge on the side of the undertail coverts that is so distinctive of Green-winged Teal, nor does that species have orangish legs. That leaves us, among the common ABA-area dabbling ducks, with that tricky duo, Cinnamon and Blue-winged teal. Though Cinnamon Teal averages warmer-colored and less-distinct markings on the belly and undertail coverts, I'm not convinced that the feature is diagnostic at the colder, more-distinct end of things, but I do know that the bird was not a Cinnamon Teal.

Doug Gochfeld took this picture of four Black-bellied Whistling-Ducks and one Blue-winged Teal at the South Cape May Meadows, Cape May Co., NJ, on 19 September 2010. Particular congratulations to Christian Nunes for getting both species correct, even if it was just "a gut reaction."

Incorrect species provided as answers:
none

Congratulations to the 16 of 16 getting the quiz correct:
Al Guarente
Tyler Bell
Pam Myers
Su Snyder
George Cresswell
Thomas Hall
Kirk Huffstater
Margie Joy
Diane Porter
Peter Wilkinson
Robert McNab
Joe Bens
Christian Nunes
Marcel Such
Chishun Kwong
Bryan Guarente

Answer: Black-bellied Whistling-Duck, Blue-winged Teal