Quiz #331 (2010-1-02) Answer

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Answer by Tony Leukering

After finally biting the bullet and telling myself that I would just have to start from scratch with the scoring spreadsheet, the original of which I lost when my thumb drive gave up the ghost (not an easy thing!), I'm finally getting around to catching up on answers for the Quiz. I apologize to all for the extreme delay in getting this done. I mean, it's now 20 Feb, and the I've only provided one of this year's answers so far! It will take a while to get caught up, but hopefully you'll hang in there. I'm particularly annoyed that I lost the files when I did, as I'd just completed writing an incredibly long answer for this quiz photo -- probably the longest of my tenure. Ah, well.

All respondents noted that this week's quiz presents a bunch of ducks, with some really obvious male Mallards among 'em. Starting there, note that virtually all the rest of the birds are similar in size and structure, which tells us that they should also be large dabblers. Note that the male Mallards all have dark heads (one might even be able to imagine some greenish aspect there), dark chests, pale bellies that contrast strongly with the chest, and white or whitish wing linings. There are six male Mallards, including four of the upper-left five birds.

Knowing that the birds are large dabblers, should enable us to eliminate nearly all other options, except for the two species of Mallard-like dark dabblers (American Black and Mottled), Gadwall, the two wigeons, and the two Northerns, pintail and shoveler. I want to head next to the fairly different birds present, the seven dark things -- three about in the middle of the flock, one almost on the bottom edge of the picture, the bird two birds behind (and above) the bottom one, and the two right-most birds. These birds show heads paler than their chests, but not as pale nor as creamy-colored as is typical for Mottled Duck. The Mexican Duck -- currently considered a subspecies of Mallard, but which has been shown to be more closely related to the other dark dabblers than it is to Mallard -- would not be quite so dark, and would/should show even paler markings on the sides and flanks. These birds are American Black Ducks.

The above means that we've identified 13 of the 18 birds and that we're going to have to deal with brown female things. I know that a fair number of birders like to duck the issue (sorry, I couldn't stop myself) of identifying brown ducks, but they're really not that hard and with so many male Mallards present, it would probably behoove us to look for females. Looking down at the bottom row, check out the left-most bird. Most aspects visible on the male Mallards are visible also on this bird: dark head and chest contrasting with paler belly and whitish wing linings. This is perfect for a female Mallard, and the bird's shape is even identical to that of the male Mallard behind it. Other similar-appearing birds can be found above and right behind the first one, three and five birds back in the same row. These birds all appear quite similar and all definitely have very pale wing linings. Of course, Gadwall, American Wigeon, and Northern Shoveler females also sport pale or white wing linings, but there are no huge bills present and Gadwall and American Wigeon have longer, more pointed tails. And, of course, female Eurasian Wigeon also exhibits a longer, more pointy tail, but they have gray wing linings. Northern Pintail females also have pointy rear ends and darker wing linings. And, well, look at that, would ya, that top-most bird has brown wing linings and a long, attenuated rear end. Yup, there's the hidden bird, right out in the open, where I like 'em! Also note that bird's slimmer build and narrower, longer wings. It even looks a bit smaller overall; again, absolutely perfect for female Northern Pintail.

I took this picture just north of Cape May, Cape May Co., NJ, on 30 November 2009. There were a lot of other birders present at the site, but they were looking in the opposite direction at some weird, pale gull thing. I think that they were saying something like "Ivory Gull," whatever that is! I provide another version of this picture, below, with indications of identification.

Seven respondents provided no incorrect species, but did not provide enough correct ones. One respondent's answer was precluded from being correct for the competition due to not providing the 'American' at the head of 'American Black Duck.' Finally, two answers were received after the deadline.

Incorrect species provided as answers:
Steller's Eider - 1
Cinnamon Teal - 1
Eurasian Wigeon - 1
Gadwall - 2
Green-winged Teal - 1

Congratulations to the 12 of 29 getting the quiz correct:
Tyler Bell
Chuck Carlson
Kevin Kerr
Mark Dettling
Peter Wilkinson
Al Guarente
Marcel Such
Joel Such
Joe Bens
Aaron Brees
Bryan Guarente
Andrea Smith-Guarente

Answer: American Black Duck, Mallard, Northern Pintail

Quiz #330 (2010-1-01) Answer

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Answer by Tony Leukering, Thomas Hall, Bryan Guarente, and Margie Joy

The first quiz of a new year and felicitations to all in 2010!

I had a lot of help writing this week's solution, more so than usual, as tern ID is such a minefield. Many birders never really work hard enough at it to become proficient at tern ID, even some with otherwise exemplary skills. I, certainly, did not conduct due dilligence on the problem for the first 20 years of my birding career (and still don't feel perfectly comfortable), so I obviously cannot blame those that don't. However, terns have a different way of doing plumage and plumage change than most other bird species, a more complex way in most cases, so this is yet another reason, among many (!), for the difficulties folks encounter when attempting identification of such.

As this venue is not appropriate to delving deeply into the identification processes of tern ID, I suggest referring to sources that do a reasonable job, including Advanced Birding (by Kenn Kaufman) and Identification Guide to North American Birds, part II (by Peter Pyle; published by Slate Creek Press). I cannot stress too much the usefulness of the two Pyle guides to birders -- if you're interested in upgrading your skills, buy the books! Of course, once you do have Pyle in hand, read the chapter on molt in part II (our understanding has changed a fair bit since the publication of part I). Then, after you've pondered it for a bit, read it again. Then, consider how what you learn creates what you see in the field. Then, read it yet again. (The usual caveat applies: I have no financial interest in any books or other such materials recommended here.)

In terns, wingtip pattern is an incredibly important ID feature. So much so, that most species can be reliably identified from wingtip pattern alone. It is, however, not enough to simply note that the wingtip has black or it doesn't. One should determine how many primaries sport black, how black the black is, where -- precisely -- the black is on the individual primaries, and what the overall appearance the distribution of black makes. As many of this week's respondents made this very argument, I will let them do the job of running us through the ID. In fact, respondents provided a variety of tacks to get to the correct ID. Bryan Guarente also supplies the suggestion that I would otherwise have made to AGE THE BIRD! Margie Joy, though she provided a way through the morass of tern ID to get to the correct solution, also made a final comment that I thought particularly appropriate in this case which I quote below, but paraphrase here: start with the obvious bits and see where that takes you!

Thomas Hall wrote:
"One can quickly discern that this week's quiz bird is a tern, one with a snow-white belly and tail, eliminating about half the field of terns with many sporting a darker tail or grayish/black belly. Add to that the fact that the three outer primaries are black -- and only those three, one can eliminate most of the others which sport none or more and that the trailing edge on the underside of the wing is not dark leaves, in my opinion, Roseate and Least terns. A look at the forehead, just barely visible, gives a hint that it is white. The beak, a small and almost unnoticeable projection from the wing, is yellowish with a black tip (Least) and not black (Roseate), and that the feet are orange-yellowish (Least) and not reddish (Roseate). Therefore, I am left with only Least Tern."

Bryan Guarente wrote:
"I am going to try to do what you have desired us to learn to do for so long: age the bird first. This, thankfully, is an easy one to age. All terns with predominantly white upper wings have a juvenile plumage that contains some spotting, barring, streaking, or other form of patterning on mantle, underside, or upper wings aside from primaries or primary tips. The other age tip we have here is the full black cap and nape. With these indicators, we know that we have an adult bird.

"Now to the most important part of this discussion aside from age: bare-parts color. The bare parts of this bird are yellow (feet and beak (yellow with black tip)). There are only two ABA-occurring terns that have yellow bare parts: Least and Large-billed. One can easily rule out Large-billed Tern on many different features: bill size, mantle color, upper wing pattern, tail color, and number of black primaries. This leaves us with the smallest ABA-area tern, Least Tern.

"Another easy method to arrive at the correct conclusion is the number of black primaries. Least Tern is the only ABA-area tern that has three [and only three] completely black primaries in its adult plumage. Roseate Tern, the only other ABA-area tern with three [and only three] primaries with black on them, has just the tips black with the rest of these primaries a varying shade of gray. Although the methods are different, both, thankfully, lead to the same conclusion."

Margie Joy summarized:
"After all that, I think that I could have gone about this in another way, starting with [any one of] the most conspicuous features, like the long and narrow wings, the black wedge on the outer wings, or the distinctive bill and leg color. One or more of these characteristics would have brought me straight to Least Tern. That might have been a simpler process; who's to say!"

I took this picture of an adult Least Tern at Norbury's Landing, Villas, Cape May Co., NJ, on 25 May 2009.

Thanks to all those playing the Mr. Bill Mystery Quiz for keeping an enjoyable endeavor going (without you, there would be no quiz) and to this week's respondents, particularly to those quoted above, for enabling me to see how folks tackled the problem. It is a learning process for me to see where folks went right, or wrong, in their identification processes, and important, as it enables me to provide better written solutions to the various problems with which I task all of you. Here's to a great 2010 Mr. Bill year!

Incorrect species provided as answers:
Common Tern - 4
Forster's Tern - 2
Sandwich Tern - 1
Roseate Tern - 1

The 25 of 33 providing the correct answer:
Kirk Huffstater
Tyler Bell
Jim Kopitzke
Thomas Hall
Al Guarente
Bryan Guarente
Chuck Carlson
Kevin Kerr
Tom Wilberding
Su Snyder
Peter Wilkinson
Jonathan Lautenbach
Margie Joy
Aaron Brees
William Velmala
Mark Dettling
Peter Burke
Louie Toth
Robert McNab
Andy Dettling
Joel Such
Marcel Such
Joe Bens
Andrea Smith-Guarente
Chishun Kwong

Answer: Least Tern