[obol] This weeks birds in hand: photo quiz

[David Irons]

Greetings All,

I sent the same list of species to Mike in response to his quiz.  However, I don't think you can make a strong case for the first bird being a representative of the Rocky Mountain subspecies (orestera)  of Orange-crowned Warbler. This subspecies, which is often referred to "gray-headed," is not a simple ID based on my recent discussions with several folks keen on getting a handle of subspecific ID of Orange-crowned Warblers and sorting out the migratory routes of the three main subspecies.  

While this bird does show some gray tones on the head, the gray is not as obvious or extensive as it generally is on orestera.  Additionally, this bird shows what appears to be whitish or at least cream-colored eye arcs, which is considered by some to be a good field mark for separating orestera and celata from lutescens.  However, I have been closely studying Orange-crowned Warblers this spring, and there have been a few birds that I would call lutescens that showed non-yellow eye arcs.  I have also seen birds that showed at least some suffusion of gray on the crown, nape, and upper back, but were otherwise greenish yellow on the sides of the head and face.  

Hatch year Orange-crowneds of all subspecies show whitish eye arcs and at least some diffuse gray on the head in fall, and I suspect some of the duller birds with non-yellow eye arcs are 1st spring birds, perhaps females.  That being said, I don't think that Quiz Bird A is off the dull end of the spectrum for a lutescens, and I have not seen definitive
works that offer solid evidence suggesting that
these subspecies can be safely separated in the field.  Dennis Vroman and Mike Patterson (both banders) are among those who I've communicated with on this issue.  I have also been in contact with Colorado birders Bill Schmoker and Tony Leukering, and neither of them has offered sure-fire ways of ID'ing orestera in the field.  I do believe that many Orange-crowned Warblers (those presenting the extreme expression of plumage characteristics) can be ID'd to subspecies, but I don't think this bird is such an individual. Further, there seems to be a significant percentage of spring birds that cannot be assigned to subspecies. 

Dave Irons
Eugene, OR

> From: 4cains at charter.net
> To: obol at oregonbirdwatch.org
> Date: Thu, 1 May 2008 23:04:35 -0700
> Subject: Re: [obol] This weeks birds in hand: photo quiz
> 
> A: Orange-crowned Warbler, V.c. orestra
> B: Orange-crowned Warbler, V.c. lutescens
> C: Wrentit
> D: Ruby-Crowned Kinglet, female
> E: Lincoln Sparrow, adult
> F: Purple Finch, adult female (although the beak looks House Finchy to me, 
> the supercilium doesn't.)
> 
> Lee Cain
> Astoria 
> 
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> obol at oregonbirdwatch.org
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