Quiz #293 (2009-2-01) Answer

Click the picture for a larger view.

Answer by Tony Leukering

I heard a great sigh of relief when this picture got posted on the Mr. Bill Mystery Quiz, as it was of a single, well-depicted bird. It's definitely a new quarter! But, of course, there's always a catch. We don't have four species of gulls to ID, but the quiz bird is a shorebird. And a drab one at that. And it has no legs!

First, let's get the bird into a general group of shorebirds. The bill rules out all of the plovers and that and the plumage rule out all of the 'odd' shorebirds (e.g., oystercatchers and avocets) at the front of shorebird taxonomy. Also, unless our quiz bird is standing in a really deep hole, our bird does not belong to one of the long-legged sandpiper genera (e.g., Limosa or Limnodromus), thus our bird is probably of that well-loved genus, Calidris. Additionally, the compactness of the bird and the not-really-overly-long bill suggest that it is one of the peeps, that group of small sandpipers that make many a birder's knees quiver.

Second, we need to age the beastie, as one should do for most shorebirds preparatory to IDing them. The bird seems to have no distinctive feathers, either bright-edged juvenal feathers or dark-centered adult alternate-plumage feathers. This makes things a bit sticky, as the bird is, thus, in basic plumage and could be of any age. Yes, the vast majority of young-of-the-year peeps retain at least a few juvenal feathers (usually scapulars or coverts) that allow for ageing, but some do not. So, we'll forego ageing for the nonce.

Assuming that our assumption about the bird being a peep is correct, let's try to whittle down the options -- there are currently nine peep options on the ABA list. Looking at our bird's wingtips, we can see that they fall short of the tail tip, and that by a fairly large margin. This, then rules out the two large, long-winged species: Baird's and White-rumped. The upperparts coloration can also help us, and the very grayish-brown look is quite different from the rich and warm brown of both Least Sandpiper and Long-toed Stint. In fact, those warm-brown species also both show more of a hooded effect with brown extending down through the throat and chest, features inconsistent with our bird. So, that's four species gone and four more to eliminate. Temminck's Stint is the odd-man-out of the remaining options, but that species, like Least and Long-toed, is a brown, hooded peep.

While it's good to have ruled out five of the nine options, that elimination does leave us with the stickiest set of four species: Semipalmated and Western sandpipers and Little and Red-necked stints. Even given good photographs, some individuals of these species are not definitively identifiable. However, we are 'blessed' with a bird with quite a long bill, and that should help us out quite a bit. The two stints still remaining under consideration do not sport such long bills, so we're left with the all-too-common conundrum of Semi vs. Western.

Our bird, unfortunately, is not foraging, so we lose some of the features that might help us ID the bird (e.g., water depth). However, a recent article on peep ID by Cameron Cox in Birding magazine (http://www.aba.org/birding/v40n4p32.pdf) makes some suggestions that are quite useful. Our bird has a substantial chest and a head that is longer than deep, both features suggesting Western Sandpiper as the ID of our mystery bird. Combine that with the long bill that tapers to a fine point and droops ever so slightly, and our initial ID firms up quite nicely. As a final minor point, note the slightly rufescent cast to the auriculars, a feature usually more noticeable on Western than on Semipalmated.

I took this picture of a basic-plumaged Western Sandpiper (probably an adult) at Stone Harbor Point, Cape May Co., NJ, on 23 September 2005, the same date on which I took the photograph that was used as Mr. Bill Mystery Quiz #168 (http://cfo-link.org/MrBill/answer.php?quiz_number=168) and which you will find in the aforementioned peep-ID paper.


Tallies of incorrect species provided in answers:
Sanderling - 1
Dunlin - 2
Semipalmated Sandpiper - 4


The 27 of 33 providing the correct answer:
Chuck Carlson
Jessica Brauch
George Cresswell
Andy Dettling
James Stephenson
Matt Webb
Chris Warren
Mark Dettling
Tara Nelson
Joe Mammoser
Thomas Hall
David Hill
Tom Parchman
Bryan Guarente
Peter Burke
Peter Wilkinson
Nick Moore
Aaron Brees
Joel Such
Marcel Such
Joe Bens
Todd Reeves
Barbara Deneen
Mark Gabriel
Chishun Kwong
Robert McNab

Answer: Western Sandpiper

Quiz #292 (2009-1-13) Answer

Click the picture for a larger view.

Answer by Tony Leukering

And you thought the gull picture was hard! At least you could see plumage characters!

I had shown this picture to a few friends to see if they really thought that the birds were identifiable. They all answered in the affirmative, but they did all have experience counting migrating waterbirds at the Seawatch at Avalon, NJ. Interestingly, the only person getting the quiz correct also has that very experience, though I hadn't shown him the picture ahead of time.

On sitting down to write this week's answer, I couldn't decide whether to start with the single most distinctive bird in our bunch of silhouetted ducks or to leave that one for last. However, since the flock of birds is mostly of a single species, I thought that I'd start there. But, before that even, I thought that I'd point out that there are three species present: the distinctive bird above the bottom line of birds and the top right individual are different species than are all the rest of the birds.

So, shape is critical if we're going to get the correct IDs, and the regulars among you know how often that I stress that feature in bird ID. As we can actually see a bit of color on the head of the bottom right bird, we'll start there. There seems to be some white on the nape and around the bill and also has some paler color on the bill that is not white but is darker than white, but paler than most of the rest of the bird. These features should take us, without passing GO or collecting $200, straight to adult male Surf Scoter. Adding in the various shape features -- long, sloping forehead; deep belly; and very short tail -- our initial guess via actual field marks is confirmed. The other two birds behind that adult male and the top left bird all share that bird's shape AND size, thus those are also all Surf Scoters, though age and sex are not particularly determinable. Common Eider, an oft-guessed species this week, would also be ruled out (in addition to the features visible on the head on the adult male) by that species' larger size (largest duck in North America) and, particularly, its longer neck.

With 2/3 of the beasties IDed, we're in much better shape with trying to ID the other ducks. Let's then head to the top right bird that seems both similar to and different from the Surf Scoter behind it. It has a longer tail, thinner neck relative to head depth, smaller and rounder head, steeper forehead, and smaller bill. The bird is also just a bit smaller (shorter, at least) than the Surf Scoter and all of these features match up quite nicely with an ID of Black Scoter. King Eider would have been hard to rule out if it weren't for the direct size comparison with the Surf Scoters, as that species is larger, not smaller, than Surf Scoter.

The final duck is obviously smaller than Black Scoter, with a much lankier look that is created by the relatively longer neck and tail and the overall longer rear end. The bird also has a fairly square head, a very thin neck, and a thin bill that seems relatively longer than the bills of even the Surf Scoters (relative to head size, of course). The features already mentioned should enable the experienced to ID this bird, as it has a fairly distinctive shape. However, those with experience watching migrating ducks (at least on the Great Lakes and on the East Coast) know that we often find other species mixed among scoter flocks. In fact, it's one of my greatest pleasures in birding to sort through scoter flocks to find the oddballs. THE COMMONEST species joining scoter flocks, at least at Avalon, NJ, is Green-winged Teal, and the features of our bird match that species precisely. Of course, if and when Common Teal (the Old World version of the species) gets split, then this bird becomes immediately unidentifiable! The other new world teal are easily ruled out by their shorter tails, thicker necks, even-larger bills, and rounder heads. The smaller diving ducks would be ruled out by a variety of features, particularly our bird's long and thin neck and square head. The large merganser species are ruled out by those species' even-longer necks and longer bills, particularly Common Merganser. Loons have much longer necks, are considerably larger than even Surf Scoter, have virtually no tail, and longer wings.

For those interested in learning more about seawatching at Avalon, check out

http://www.birdcapemay.org/seawatch.shtml.


Six players provided responses without incorrect answers but without enough correct answers. Additionally, one player got all three species correct, but provided another species not present in the picture. Finally, the list of species provided as answers (including all four of the world's eiders!) was probably at least as long as for any previous Mr. Bill Mystery Quiz iteration, indicating, no doubt, two things: the difficulty of the quiz and the lack of experience that most birders have identifying ducks (flying or otherwise) at distance/in bad light. For those used to spending time on hawkwatches, the skills required at counting migrating waterbirds are the same (flight style, shape), but the problems are magnified by a MUCH LARGER SUITE OF SPECIES. Truly successful waterbird counters get incredibly good at this!

I took this picture (actually part of a larger, more individual-rich picture) from the Cape May - Lewes ferry (again!) just outside Lewes harbor, DE, on 18 October 2008. I assume that had I provided the picture's location, I would have received fewer guesses including various species of eider.

With this quiz, the first-quarter competition has come to a close. And with none of the leaders getting either of the last two quizzes correct (since the last publication of the leader board), those standings remain. The four in the lead with the most correct of 13 (8) were Tyler Bell, Aaron Brees, Andy Dettling, and Peter Wilkinson. However, Tyler and Peter led over the other two in total species identified correctly (taking into account the numerous multi-species quizzes this quarter) and, in fact, the two of them tied in both tie-breakers, so a flip of a U.S. quarter reveals that the winner of this quarter's competition is... (drum roll, please) ...


Peter Wilkinson, our inveterate player from across the pond! Congrats, Peter, you have won the prize of a year's membership in CFO. I'll leave it to the CFO board to figure out how to get his journals across the pond.

Tallies of incorrect species provided in answers:
Brant - 1
Common Eider - 6
King Eider - 3
Hooded Merganser - 1
Red-breasted Merganser - 4
Spectacled Eider - 1
Steller's Eider - 1
Long-tailed Duck - 1
White-winged Scoter - 1
Gadwall - 1
Red-throated Loon - 1
Common Loon - 1
Harlequin Duck - 1
Canvasback - 1
Northern Pintail - 1
Common Merganser - 1
American Black Duck - 1


The 1 of 22 providing the correct answer:
Sean Fitzgerald

Answer: Green-winged Teal, Surf Scoter, Black Scoter