Monday, April 20, 2009

Quiz #296 (2009-2-04) Answer

Click the picture for a larger view.

Answer by Tony Leukering

Well, another easy one -- an apparently wee beastie, olivaceous above, wing bars, green wing and tail edging, big eye ring, white-fringed tertials. Could things really be this easy, with the bird being a Ruby-crowned Kinglet? The history of this quiz suggests that the answer to that question is, "Probably not." Of course, there have been a few quizzes that were....

This week's quiz bird does sport a lot of Ricky field marks. (For those wondering who Ricky is, that is simply the pronunciation that I use when saying the four-letter code for Ruby-crowned Kinglet -- RCKI.) However, there also appear to be some inconsistencies with that ID. This sort of thing being one of my favorite topics, I'll expound here. In my experience, ID mistakes often happen because a bird shows field marks of a particular species and birders jump to that conclusion and overlook those various field marks that don't match the ID arrived at so quickly.

Our bird's eye ring seems a bit buffy for RCKI and the bill a bit thick. Of course, either or both of those features might be affected by the odd angle of the quiz bird's head, so let's continue. In fact, we'll continue to the most obvious two features that rule out Ruby-crowned Kinglet:

1) the bluish-gray legs (RCKI sport black legs with yellow soles to the toes)
2) the single most-useful feature, the green fringing of the secondaries and primaries extends all the way to the bases of those feathers and to the tips of the greater coverts that form the lower wing bar on our bird. That is, there is no black bar cutting across those feathers that separate the green fringing from the wing bar that is so typical of RCKI. In fact, it's typical of both of our kinglets and an excellent field mark for the genus.

Well, with kinglets removed from consideration, we'll have to be a bit more exhaustive in our ID attempt. There are quite a few greeny birds with white wing bars in the ABA area, so we might be here a while. However, our bird's bluish-gray legs also, nicely, rule out the majority of those other options, including (Hallelujah!) those easy-to-ID birds known as Empidonax flycatchers!

Just to be thorough, our bird's short tail also goes some way to ruling out the Empies -- at least, the long-tailed species, though Hammond's and Least might easily have a tail this short. However, the aforementioned thick bill should also rule out the Empies, as does the thick eye ring broken quite obviously at the top.

If the bluish legs hadn't gotten us there, certainly the lack of other options at this point would, so we'll buzz through the vireos (a group nearly defined by bluish legs) looking for our bird's ID. Within the vireos, we can rule out all the plain-winged and superciliaried species. Our bird is too dull for Yellow-throated, White-eyed, and Thick-billed and is too green-headed for even the dullest of Black-cappeds. Our bird is too bright for Gray and Plumbeous. Cassin's Vireo can match our bird's plumage quite easily, as can some of the duller Blue-headeds, particularly the Appalachian form alticola. Some forms of Bell's Vireo might be reasonable candidates, too. However, our bird's eye ring is broken on top, ruling out all but Thick-billed and Hutton's. Thick-billed, as earlier stated, is brighter, with more-yellow underparts and it's eye ring is split (or virtually so) in multiple places, unlike that of our quiz bird. Oh, and the National Geographic Guide considers it so easy to confuse Ruby-crowned Kinglet and Hutton's Vireo, that it provides (at least through the 4th ed., the version I have in my hand) a thumbnail of RCKI on the vireo plate.

I took this picture of a Hutton's Vireo at Stinson Beach S.P., Marin Co., CA, on 22 November 2007.

Answers from two respondents were precluded from being correct for the competition, as they omitted the capitalization of 'vireo.' Additionally, another respondent's answer would have been precluded, had it been correct, for omitting all capitalization in the species name provided (please, please, read the rules).

Finally, one respondent thought that there would be more RCKI answers than HUVI answers, but, as you can see below, our respondents did much better than that.

Tallies of incorrect species provided in answers:
Ruby-crowned Kinglet - 6
Alder Flycatcher - 1
Hammond's Flycatcher - 2
Orange-crowned Warbler - 1

The 25 of 35 providing the correct answer:
Chuck Carlson
Thomas Hall
Tyler Bell
Chris Warren
George Cresswell
Aaron Brees
Robert McNab
Peter Wilkinson
Tara Nelson
Al Guarente
Mark Dettling
David Hartley
Terry Nelson
Marcel Such
Tucker Lutter
Lisa Clements
Rick Clements
Su Snyder
JOel Such
Mark Gabriel
JOe Bens
Nick Moore
Chishun Kwong
Bryan Guarente
Andy Dettling