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Ouch! This week's quiz bird is a member of the genus Corvus and with no sound nor flight style to use for ID, it's a hard one. We should first decide whether 'tis a raven or a crow. The shortish and fairly squared tail rules out most individuals of the two ABA-area raven species, as does the fairly short bill. While some may complain that separating the four ABA-area crow species is very difficult, I think that it's considerably easier than raven ID! Besides, we do have the red-text caveat that the bird is not a Northwestern Crow (regardless of what that taxon really is), so buck up and read on.
Those folks that play both of the online photo quizzes that I run, may have an advantage in this quiz's solution and you may wish to refer to the picture in the 22 June 2009 quiz on the Colorado Field Ornithologist's website. One might do that because the two pictures ran concurrently for a week and they're both of crows! So, what's a responsible respondent to do -- think that they're both the same species (which many know would not be at all beyond me), randomly pick two species and guess one for each, or should s/he buckle down and learn how to distinguish crows in flight. As I consider these quizzes as education venues, I'll be running us through the last of these three options.
So, we've got three species to consider: American, Fish, and Tamaulipas. As one respondent noted, it's a good thing that Sinaloa Crow (formerly part of Mexican Crow until the split creating Tamaulipas and Sinaloa crows) does not occur in the ABA area. Yet. They're quite similar, being lanky, glossy crows of coastal (and near-coastal) areas that almost certainly share a fairly recent common ancestor. In fact, Tamaulipas may be the easiest species to exclude, as our quiz bird is too chunky; too wide-winged; and, perhaps, too short-tailed for that taxon. I could not run down on the internet any pictures of the species in flight -- none in the VIREO collection and none on Flickr! Doesn't anyone have such? Despite this, my recollection of the species is of a long, lanky, narrow-winged, long-tailed crow that is quite different (in a subtle, crow-kind-of-way) from the other crows with which I am familiar.
As many ABA-area birders live in or near areas with both American and Fish crows, it ought to behoove them to learn the salient ID characters. However, from personal experience, I know that many birders believe that they're not identifiable without vocal cues (having even heard a field-trip leader in NJ say this to participants!). While ID may be difficult, it is in no way impossible without vocal cues. Proportions of wing length and tail length are useful (and were the cues that I used in my first stint living on the East Coast way back when). However, Michael O'Brien, who edited the text and artwork of the most recent edition of the venerable Peterson guide, put me onto another character that is more-sure and doesn't require a lot of experience in judging wing and tail proportions of the two species. It is also one that he made sure to illustrate properly in the new Peterson guide (white cover with flicker). In fact, despite considering one-character ID suites anathema, I'm going to head down that road with this set of two crows.
What we need do is study the wing formulae of the two birds. American Crow has more fingers — and longer fingers — than does Fish Crow ('fingers' being outer primaries, the tips of which are visibly separate from their neighbors on the spread wing, not cheek-to-jowl like the inner primaries and secondaries). Knowing that crows have ten primaries (as do all of the first half (or so) of the passerines) and counting backward from the outermost primary (primary #10; p10), one can see that p5 is just a bit shorter than is p6 and is just longer than, and with its tip nearly adjacent to (that is, not all that separate from), p4. On the CFO quiz crow, however, p5 is quite a bit shorter than is p6 and separate from and quite a bit longer than is p4. While one might think that this would be a difference impossible to discern in a flying crow, it's not actually all that difficult, as crows fly with fairly slow wingbeats, but does require at least reasonable views of the bird in question.
Now that we all know this difference between American and Fish crows, we all know that this week's quiz bird is a Fish Crow (whose picture I took 5 March 2009 at Florence, Burlington Co., NJ).
The following people (listed by submission date beginning with the earliest) submitted correct answers for the June Bird Photo Quiz—Fish Crow:
The following list shows the number of submissions for each species guessed.
The photo and answer for this quiz were supplied by Tony Leukering.