Monday, June 1, 2009
Click the picture for a larger view.
Answer by Tony Leukering
First off, I apologize for the obviously misnumbered quiz (the second of two Quiz #301s; I fixed that problem after the fact and have corrected all the succeeding incorrectly numbered quizzes.
Though only four of 22 respondents answered with an incorrect species, ten provided answers without enough correct ones. One of these answers, provided only one species and that one was missing capitalization on the second word, so would have been precluded from being correct for the competition even if it had provided all three species. I took the quiz picture at Lily Lake, Cape May Pt., Cape May Co., NJ, in December 2008, and those data should allow many respondents to suspect where they might have gone wrong.
So, yes, another tricky multi-species quiz. We obviously have ducks and geese, so is the tricky, "hidden" species a duck or a goose? Let's start with the big, obvious beasts. The size of these geese make it obvious (or not) that I was trying to get folks to decide between Canada and Cackling geese, as -- in comparison with the ducks -- they're obviously not Giant/Moffit's Canada Geese -- the really big boys. So, are these smallish Canadas or largish Cacklings? Well, to effect that decision, perhaps I could suggest a recent paper in North American Birds by Steve Mlodinow et al. (Distribution and Identification of Cackling Goose (Branta hutchinsii) Subspecies, pp. 344-361) -- a fairly exhaustive, but preliminary, treatment of the various races of the species with reference to its separation from the smallest of the Canada Goose races, Lesser Canada Goose. (I assume that back issues are available from the publisher, the American Birding Association (www.aba.org).)
However, we'll press on. Separation of these two species can be quite tricky, but overall size, head shape, bill size and shape, neck length, and some other "soft" characters can, together, provide for definite (or nearly so) IDs. Of course, to utilize many of these features, good profile views are useful/mandatory, and most of our quiz geese are not providing such. We'll cut to the chase, though, and look specifically at the 2nd and 4th geese from the left. The 4th one, with its neck stretched upward, has the rounded crown and long, tapered, and relatively thin-based bill typical of all races of Canada Goose; not to mention an apparently long neck. Cackling Geese tend toward blocky heads with squared-off crowns, deep-based-but-short bills, and short necks. Those features are all found on the 2nd goose from the left. Having spent a LOT of time studying Cackling Geese in its various forms but having seen but not particularly studied Canada Geese subspecies -- at least, the more eastern ones, I don't really know to what subspecies the 4th goose from the left is referable. Though I identified the rest of the geese (except, perhaps, for the more problematic 1st goose from the left which might be a Lesser) as Canadas, it doesn't really matter, as there are, currently, only two species of white-cheeked geese and we've already scored both of 'em. Additionally, Cackling Goose is not at all common in New Jersey, so the probability of a single lake hosting at least eight Cackling Geese is a bit remote.
Onto the ducks.
The bird just right of center in the front row whose body is in profile sports the obvious white crown, pinkish-rufous sides, white flank, and black vent area typical of male American Wigeon. The next two ducks to picture left of it are of the same persuasion, as are two of the birds in the back right and the two in the back center. All of the rest of the ducks are female wigeon (warm-colored sides and with tertials not obviously gray rules out female Gadwall), but of which species? The leftmost duck has the vaguely contrasting gray head typical of female Americans, but we cannot really see the other important features -- bill with black basal border (or not), gray (or white) second secondary, face pattern, head color, or axillar color -- well enough to be certain of our initial ID. In fact, this individual is the one that we can see best and if we cannot ID it, I do not hold much hope for IDing the rest of 'em. Yes, the female in the front row swimming away from us seems to have a warmer brown head than does the leftmost duck, but they're in such different planes that I'd certainly not take that one to the Eurasian Wigeon bank. Thus, given this single picture, I don't see any way to definitively ID any of the ducks to other than American Wigeon.
As I often do, I took this picture specifically for this venue for two reasons:
1) the "hidden" Cackling Goose among the locally much-more-common Canada Geese and
2) the fact that the female wigeons were probably not going to be specifically identifiable.
Recall that there are many instances in the field where individual birds are unidentifiable given the views provided. Additionally, a single picture can often be very misleading depending upon exposure, lighting, posture, etc., etc., etc. Going out on a limb and identifying these technically unidentifiable birds (in the field or in pictures) may not lead to any problems, but, in my opinion, accuracy is more important than identifying every bird (though I do encourage at least attempting ID of every bird!).
The Cackling Goose pictured was present for some time in the Cape May Point area during the early part of winter 2008-2009.
Tallies of incorrect species provided in answers:
Eurasian Wigeon - 2
Gadwall - 2
The 7 of 22 providing the correct answer:
Answer: Canada Goose, Cackling Goose, American Wigeon