Monday, April 13, 2009

Quiz #295 (2009-2-03) Answer

Click the picture for a larger view.

Answer by Tony Leukering

As noted by all respondents, this week's quiz bird is a duck. Those providing their rationale took a variety of tacks to get to the right answer. In fact, despite our inability to determine most of the bird's upperwing pattern -- often a crucial part of flying-duck ID, any number of ways can get us to this week's correct answer. Tne most efficacious among these might be the bill (black), the chest (vermiculated), speculum (there is quite a bit of white on a number of secondaries), the strong gray aspect to the body plumage, and the bit of rufous in the median or lesser coverts (it's a bit hard to tell exactly to which tract those feathers belong).

Quite a few ABA-area ducks sport all-black bills in one sex and/or the other, including Fulvous-Whisting-Duck, Gadwall, Falcated Duck, all four teal, Northern Pintail, Canvasback, all three scoters, Harlequin Duck, the two goldeneyes, the two small mergansers, and the two stifftails (Ruddy and Masked ducks).

Starting with the chest would rule out all diving-duck options, but leave us with nearly all of the dabbling-duck possibilities.

Starting with the white in the speculum, we would begin with Gadwall, both scaup, Tufted Duck, White-winged Scoter, all three Bucephala, all four mergansers, and Masked Duck. Hmm, note the near lack of correlation between this solution set and the two above?

The gray body plumage, including the chest, would leave a solution set starting with Gadwall and ending with Falcated Duck (a couple of fairly closely related beasties).

Finally, the solution set resulting in starting with rufous median and/or lesser coverts is exactly one species long: Gadwall.

I took this picture of a male Gadwall flying up the Arkansas River at Valco Ponds S.W.A., Pueblo Co., CO, 20 December 2008 on the Pueblo Reservoir CBC.

One respondent involved her/his stab at the species ID with his/her guess as to the bird's age and sex. Fortunately for that person, all aspects of that answer were correct. However, if s/he had missed hit on even one of those features other than ID, the response would have been considered incorrect for the competition, though that person's name would have been listed as being correct. Please, when submitting an answer for the quiz, separate your guesses as to age, sex, subspecies, political persuasion, or any other bit that you care to guess on from your answer as to the ID of the species. Finally, that respondent may not know that guessing the age on this bird may have sent the answer astray. That is because 1st-cycle male dabbling ducks (for the most part) look very much like older males, however this bird's tail is not worn as would be typical of an immature male.

Tallies of incorrect species provided in answers:
Green-winged Teal - 1

The 31 of 32 providing the correct answer:
Peter Wilkinson
Robert McNab
Joel Such
Chris Warren
Aaron Brees
George Cresswell
Todd Reeves
Barbara Deneen
David Hartley
Jonathan Lautenbach
James Stephenson
Ned Keller
Peter Burke
Victor Germain
Andy Dettling
Tom Parchman
Tyler Bell
Marcel Such
Al Guarente
Mark Dettling
Thomas Hall
John Bissell
Chuck Carlson
Terry Nelson
Su Snyder
Bryan Guarente
Mark Gabriel
Matt Webb
Chishun Kwong
Nick Moore
Andrea Smith-Guarente

Answer: Gadwall