[Mystery bird] Orange-crowned Warbler, Vermivora celata, photographed at the Big Sioux Recreation Area near Brandon, South Dakota. [I will identify this bird for you tomorrow]
Image: Terry Sohl, 10 May 2009 [larger view]
Photo taken with a Canon 50D, 400 5.6L.
Please name at least one field mark that supports your identification.
I'm going with orange-crowned warbler on this one, based on the "broken eye-ring", "blurry olive streaks below" (which I can sort of convince myself I'm almost seeing), and "yellow undertail coverts" (Sibley).
I would have said OC Warbler too, but this could be a trick question ... It could be a Tenn. Warbler. It is hard to see the eye marking, but it is similar, and ... oh, no, wait ... look at the tail. Orange crowned warbler. Fur shur.
Well that was fast... Have you seen .jaypg yet? ISTR that you've been caught in a similar position....
What an absolutely charming picture!