Quiz #282 (2009-1-03) Answer

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Answer by Tony Leukering

Yet another multi-species quiz and another one that respondents had some problems with. The surf in the foreground suggests that we're on a coast somewhere, but which coast? And, does it really matter? We need to identify all the species, regardless. One point to make up front is that all of the birds look to be roughly the same size except, perhaps, for the browner bird on the left side.

Since the bird that we can see best is the front one, we'll start there. An obvious blackish duck with a distinctly paler head -- or, at least, much of it. Though we might start thinking along the lines of American Black Duck, closer scrutiny should allow us to see the blackish crown and black bill that are features inconsistent with such an ID. In fact, this bird can really only be a female-plumaged Black Scoter, and that ID certainly works with the surf. (Ruddy Ducks are much smaller than scoters and typically are not found in the surf.)

On the back row of birds, we can see two birds with distinct white patches on the head, though where, precisely, those patches are might be in some doubt. The right of these two birds might suggest to some an ID of American Coot (if the white is the bill), but an American Coot in the surf with one or more scoters would be a bit of an odd sight, as the species is not exactly fond of saltwater. If we look at the left of those two, we can see that the large white patch is on the nape and that makes our job easy: male Surf Scoter. Thus, we should be able to readily ID the other such bird as another male Surf Scoter.

The left-most bird in the back row, with its two white facial spots should be either a White-winged Scoter or a Surf Scoter, as Harlequin Duck should be obviously smaller than the nearby male Surf Scoter. The front white patch appears to abut the base of the bill well behind the tip of the bill, thus this should be a female-plumaged Surf Scoter -- White-winged Scoter has a much more slanting meeting of feathering and bill base that would bring the front white patch much more forward.

The bird third from the left looks to be another female-plumaged Black Scoter, with its fairly distinct paler face. That leaves us with two nearly all-dark ducks, one of which is tucked, sleeping. Though neither of them shows the head pattern of female Black Scoters, neither shows the distinct face patches of either of the other two species of scoter. The right one, though, does have a hint of such, and that alone should tell us that it's a Surf Scoter, probably an older female, as this seems to be a strong tendency in this species; I don't know that White-winged Scoter sports such a plumage. More importantly though, neither of these birds looks substantially bigger than the other scoters, which White-winged would.

That leaves us just one more duck to ID, the somewhat larger brown bird on the left side. Well, when dealing with scoters and somewhat larger brown birds in surf, one's mind really ought to head to the eiders. Our bird has a fairly blocky head and a fairly vertical meeting of facial feathering and bill base, two points consistent with an ID of King Eider and inconsistent with the features of Common Eider. Additionally, the facial pattern is certainly not that of a Spectacled Eider and the bill is much too big for that of a Steller's Eider.

One respondent provided an answer with no incorrect answers, but with not enough correct ones and a few respondents provided all the correct species, but also added at least one incorrect species, typically White-winged Scoter. I took this picture of five Surf Scoters, two Black Scoters, and one King Eider in the surf at Sea Isle City, Cape May Co., NJ, on 3 November 2008. Correct answers came from respondents in Colorado (3), Michigan, New York, Iowa, and Idaho. Congrats on correctly assessing a difficult quiz picture.

Tallies of incorrect answers for quiz species:
White-winged Scoter - 8
Common Eider - 13
Bufflehead - 1
American Coot - 1
Harlequin Duck - 1
Ruddy Duck - 2
Mallard - 1
Lesser Scaup - 1

The 7 of 25 providing the correct answer:
Hugh McGuinness
Thomas Hall
Charles Swift
Andy Dettling
Brandon Percival
Aaron Brees
Chishun Kwong

Answer: Black Scoter, Surf Scoter, King Eider

Quiz #281 (2009-1-02) Answer

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Answer by Tony Leukering

This week's quiz was a doozy, though two of the species present were correctly IDed by all: Northern Gannet and Great Black-backed Gull. At that point, nearly all respondents went wrong somewhere, with six respondents providing answers with all species correct, but without enough species listed and three respondents getting all species present correct, but providing answers with too many species.

When I took the picture, I didn't really see the Northern Gannet (a nice adult), because I was actually taking pictures of the raptor. That bird was crossing Delaware Bay headed south as I was taking the ferry north from Lewes, DE, to Cape May, NJ, on 18 November 2008. The gulls, being gulls, objected to the raptor's presence and were mobbing it. The Northern Gannet was just minding its business and was simply passing through.

So, the real trick of this quiz was to correctly ID the raptor and each of the gulls. With the provided caveat that there were no local rarities in the picture, we can safely eliminate all species that would be rare on or around Delaware Bay, which helps us tremendously with the gulls.

As the raptor was the focus of the picture, we'll start with it. Though quite a few species were provided as answers, the raptor's strong buffy-orange coloration on the underparts that lack streaking; the narrow and long wings; the long, yellow legs; and the long and strongly-banded tail really leave us with no options other than a juvenile Northern Harrier (and almost certainly a male, due to the narrow wings).

Now, onto the gulls. With the direct size comparisons with the two "Northern" birds, we should be able to determine that all six of the gulls are sizable (as noted by a few participants). Taking the large size and combining it with the list of Delaware Bay gulls, we should be left with a short list of options: Herring, Iceland, Lesser Black-backed, Glaucous, and Great Black-backed. Iceland is probably on the small side for our quiz birds, but I'll retain it for the nonce.

But, not for long, as we can eliminate both white-winged gulls because all of our gulls have at least some distinct black on the tail, a feature not present on either Iceland or Glaucous gulls, no matter the age. With a somewhat tricky triad of gulls remaining, I thought that I'd start with one gull in particular -- the top right gull with the black-tipped white tail. That bird appears to be heavily checkered on the wings and back and the crispness of that plumage suggests that it is a juvenile (in juvenal plumage) or one that has initiated its pre-formative molt, but one that is still well less than a year old. The fact that it has a tail band rules out Herring Gull and the bird's pale greater coverts contrasting with the dark secondaries means that we can rule out Lesser Black-backed Gull. So, this bird is a first-cycle Great Black-backed Gull.

Looking at the rest of the gulls, we should be able to note that there are four others that share our initial gull's pattern of white underparts and a black-tipped white tail. Additionally, those four are also quite large so I feel comfortable calling all of them first-cycle Great Black-backeds, too. That leaves us with the dark-mantled gull in the upper left, the gull directly above the Northern Gannet, and the bottom right gull to ID. The first of these is the one that, I believe,
caused more respondents problems than any other. Ageing the bird should help us. The presence of black in the tail means that it's not a full adult, but the nearly all-pale bill and the nearly uniform coloration of the upperparts means that it's not a very young bird, either. These features tell us that it's a third-cycle gull. By enlarging the picture and looking at the wingtip, we can see that the outermost primary is extensively tipped white, which is all we need to make the ID:
Great Black-backed Gull. Additional features, such as the size of the head and bill, point in that direction and away from Lesser Black-backed Gull. Finally, in my experience, most North American Lesser Black-backed Gulls of this age have much more black on the bill.

For the gull above the gannet, note that the black wingtip contrasts strongly with the paler gray inner wing and that the bill is mostly pale. The lack of any mirrors on the outer primaries and the large amount of black on, at least, the outer part of the right side of the tail should tell us that it is probably younger than our third-cycle Great Black-backed Gull. The bill and tail features also helps us to eliminate Lesser Black-backed from consideration, as a second-cycle LessBack would have more black in the bill and, probably, less black in the tail. That leaves us with an ID of Herring Gull.

Our final quiz bird in the picture is the full-spread bird in the bottom right. We should notice that it has a large mirror on p10 and a small one on p9, so its wingtip pattern is very adult-like. However, its tail still has a fair amount of black, so it, too, is a third-cycle gull. The black on the tail is too extensive for a third-cycle Great Black-backed and probably too extensive for Lesser Black-backed. However, this bird also has pink legs and only slight contrast between the color of the wing linings and that of the underside of the secondaries, the latter meaning that the bird is a paler-mantled gull.

Tallies of incorrect answers for quiz species:
Glaucous Gull - 1
Peregrine Falcon - 1
Ring-billed Gull - 3
Lesser Black-backed Gull - 8
Thayer's Gull - 1
Sharp-shinned Hawk - 1
Laughing Gull - 2
Cooper's Hawk - 1
Merlin - 1
Iceland Gull - 2


The 1 of 23 respondents providing the correct answer:
Robert McNab

Answer: Northern Gannet, Northern Harrier, Herring Gull, Great Black-backed Gull