Monday, January 12, 2009

Quiz #282 (2009-1-03) Answer


Click the picture for a larger view.

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