Monday, May 3, 2010

Quiz #347 (2010-2-05) Solution

Click the picture(s) for a larger view.

Answer by Tony Leukering

Too many birders focus their identification effort on that perfect field-guide view of the bird in profile with particular attention paid to those oft-critical features of head and wing. Well, those two features are not exactly presented to best advantage in this week's quiz photo. I assure you that this was intended, as I could have "photoshopically" removed both features and not impacted the identifiability of the bird at all! As with many of the quiz photos that I present in this venue, paying attention to other parts of the bird's shape or plumage is the take-home message.

This week's quiz bird is a small one, as its size comparison to the pine's needles should prove to us. While the species of pine -- one of the pinyon pines (short needles in fascicles (bunches) of two) -- is not critical to the bird's ID, it is helpful, as it suggests that the picture was taken in the west.

Our bird has dark legs, white underparts with black flank streaking, white undertail coverts, a tail that appears white underneath and gray above, gray wings with the suggestion of white wingbars, black streaking on the back, gray neck, and an interesting combination of colors on the head. However, I'm going to ignore the head for a while, because this bird is identifiable without it.

Restricting initial efforts to small passerines with the aforementioned color and pattern of the flanks and belly, our list of possibles is restricted to some warblers (Yellow-rumped, Golden-cheeked, some Hermit x Townsend's hybrids, Black-and-white, Black-throated Gray, Yellow-throated, Grace's, Blackpoll, Ovenbird, Northern Waterthrush) and Lapland Longspur, with the size (just too small) and perch site eliminating the longspur. Leg color eliminates Blackpoll, Ovenbird, and the waterthrush. The unmarked white undertail coverts eliminate Golden-cheeked and Black-and-white. Lack of significant amounts of dark at the base of the underside of the tail rules out Yellow-rumped. These reductions leave us with just four warbler species (and a hybrid), all with a particular defining character: they all share the feature on the folded tail of being nearly all white below.

Now, we will need strong focus on the precise undertail pattern. As our quiz bird lacks any suggestion to dark corners at the tail's base, we can rule out Yellow-throated. The very small amount of dark at the right tip of the tail appears to be restricted to the outer web of the outermost rectrix. On Hermit, Townsend's, and Black-throated Gray, the dark here bleeds across the shaft of the outermost tail feather into the inner web, ruling out those species and any hybrid pairings of them.

Were we to make this ID in the field, we might withhold final judgment based on our interpretation of the undertail pattern for confirmation with other noted features. In our quiz picture, our bird's gray crown with thin, black streaks, strong black lateral crown stripe, bright yellow supraloral stripe/patch, and black back streaking make that confirmation.

I took this picture of a male Grace's Warbler south of Walsenburg, Huerfano Co., CO, on 22 May 2005. I have provided another view of the same bird from the same day, below, one in that classic field-guide view.

Eight players are currently tied atop the leader board with perfect 5-of-5 scores in the quarter's competition.

Incorrect species provided as answers:
Black-throated Gray Warbler - 1
Golden-crowned Kinglet - 1
Verdin - 1

Congratulations to the 23 of 26 getting the quiz correct:
Aaron Brees
Jeff Jones
Nick Komar
Tyler Bell
Liston Rice
Peter Burke
Al Guarente
Dave Elwonger
Kevin Kerr
Kirk Huffstater
George Cresswell
Robert McNab
David Hollie
John Bissell
Thomas Hall
Margaret Smith
Margie Joy
Marcel Such
Joel Such
Peter Wilkinson
Joe Bens
Chishun Kwong
Chris Warren

Answer: Grace's Warbler