Friday, December 26, 2008

Quiz #279 (2008-4-13) Answer

Answer by Tony Leukering

This week's quiz bird, with its strong side/flank streaking and large white tail spots is a warbler, and a Dendroica warbler at that. Yes, some other warblers have white tail spots, but none of those
have such obvious streaking on the underparts. The combination of side/flank streaking; unstreaked white undertail coverts; and large, white tail spots leave us with a few options, notably Cape May, Magnolia, Yellow-rumped, Black-throated Green, Townsend's, Black-throated Gray, Blackburnian, Yellow-throated, Grace's, Cerulean, and Blackpoll warblers. The ground color in the sides/flanks appears buffy-brown, not yellow, and that should do a tremendous job of whittling down the options to just three: Yellow-rumped, Yellow-throated, and Grace's.

Now, let's move to the tail pattern, a feature that many getting the wrong answer failed to fully consider. The pattern of the tail from underneath is an excellent ID feature that is, unfortunately, overlooked by most birders. Two guides treat this aspect of warbler anatomy well, The Sibley Guide and, particularly, the Peterson Warblers guide. In fact, the plates showing this feature in the Warblers guide are probably my favorite of all plates in all North American guides.

For those that may have objected to my wholesale removal of possibilities above may like to know that tail pattern does just about the same job for those species deleted from consideration as did side color. Magnolia Warbler has a white base to the tail and a wide, square-cut black tip; Cape May and Blackburnian warblers lack our quiz bird's black base to the tail, at least on the outer part. Our bird has a thin black base (which separates the white tail spots from the white undertail coverts), a wide white middle, and a thin black tip. Grace's Warblers and adult Yellow-throated warblers sport white bases to the tail and all ages of Yellow-throated have a white tail tip.

I took this picture of an immature, probably female, Yellow-rumped (Myrtle) Warbler on 22 October 2008 at Cape May Point S.P., Cape May Co., NJ. I provide, below, the picture taken of the bird immediately prior to the quiz picture.

Tyler Bell survived the carnage of the last two quizzes of the quarter to win the competition outright (with 11 of 13), beating Peter Wilkinson by one correct answer. Five others came in with nine of 13 correct. So, kudos to Tyler for winning this quarter's prize, a $25 gift certificate redeemable on the CFO website (!

As for the annual competition, of the 171 people that provided at least one answer this year, Chris Warren takes bragging honors and the $100 CFO website gift certificate, with 42 of 52 correct answers. Behind Chris, Christian Nunes beat out Aaron Brees (both with 39 correct) on the strength of the first tie-breaker -- total number of species correctly identified (which takes into account multi-species quiz pictures), 54 to 52, for second place. Interestingly, Rachel Hopper, our inveterate webmaster, got 36 correct and didn't play at all in the fourth quarter! Thanks, Rachel, for your interest in the quiz and for all of your hard work making the CFO website what it is!

Tallies of incorrect answers for quiz species:
Magnolia Warbler - 3
Black-throated Gray Warbler - 1
Cape May Warbler - 3
Blackburnian Warbler - 4
Sage Thrasher - 1
Northern Waterthrush - 1
Northern Mockingbird - 1
Eastern Bluebird - 1
Pine Warbler - 2
Townsend's Warbler - 1
American Pipit - 1
Cerulean Warbler - 1

For only the second time in my tenure as Mr. Bill, there were no correct answers submitted.

Answer: Yellow-rumped Warbler