Monday, December 31, 2012

Happy New Year!

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[Red-winged Blackbirds, Bent Co., CO, 14 December 2006; Photo by Tony Leukering]

The Colorado Field Ornithologists wishes you and yours a wonderful new year filled with birds.

The CFO Photo Quiz is on hiatus, indefinitely, while we ponder how to make the quiz more interesting and useful and how to encourage more participation.  Comments and suggestions are welcome.

Monday, December 17, 2012

Quiz #479 (2012-4-11) Solution


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Solution by Tony Leukering

This quiz was incredibly tricky, with an immature gull and some fuzzy ducks. I'll start the solution with the relatively straightforward individual, the yellow-billed, green-headed thing in the bottom right of the picture. In the ABA area, there is only one species that sports that combo, Mallard. The next-easiest bird is probably the sleeping duck in the bottom left. It has a blackish crown contrasting with a brown neck and white cheek and brown sides contrasting with darker wings and with those darker wings also contrasting with the brown neck. The cheek patch is too large to be that of a female Bufflehead and the brown hindneck contrasting with both the crown and the darker wings is not a feature of any Bufflehead plumage. The brown neck and sides also rules out Horned Grebe, which always has a blackish hindneck.

Now, things get even more problematic. Probably the first problem to tackle at this point is deciding how many birds are in the picture, while the next thing may be deciding how many are identifiable. Here's is my take on both problems. There is an obvious duck behind the Mallard that has a sizable white patch somewhere and there is at least one duck in the shade under the vegetation just right of the gull's right wingtip. Though there might be two ducks together in the shade, I don't believe that anyone can make a convincing case for any more birds and that's if you could convince me that there were definitely two ducks together in the shade. The browny-gray aspect to the back right duck suggests Gadwall to me and that white bit might be part of the bird's speculum, which would be definitive in my mind if I could convince myself that white was, indeed, part of the speculum. I cannot so convince myself, therefore, I consider this bird to be unidentifiable. The bird in the shade, seems to have a large patch of white on what might be the chest, but it definitely has a black vent area contrasting somewhat with what appears to be a gray side. So, though the back end of that bird suggests Gadwall to me, male Gadwalls don't sport anywhere near that large a white patch anywhere. I also considered male Mallard (there is a suggestion of white in the tail) and male Northern Pintail for that bird, either of which could help explain the white bit, but since it seems to contrast so strongly with the apparently gray side, I am unsure of what is going on there. Additionally, I see enough evidence to suggest that there are two birds back there, one behind and slightly right of the one that we can see even remotely well. If that is the case, I can then not even decide to which bird that big white patch belongs. Thus, I consider this bird (or these birds) to be unidentifiable.

Here's the tricky part (Fig Newtons, anyone? Yes, my brain is very weird, I remember this one quite vividly from my childhood), the gull. When I started writing this solution, I was amazed at the large number of respondents that thought that the gull was of a different species than I identified it as. So, I corresponded with others that know both of the suggested species and have come to the conclusion that I labeled the bird correctly in the first place. So, bear with me, this may take a while.

First off, we need to age this thing. The lack of any sort of gray in the mantle and the very pointed outermost primaries tell us that this is a gull in its first plumage cycle. The bill being all black assists us in that determination and also helps us rule out California Gull. The evenness of the color tone of the bird and the solidly dark tail really leave us only a few species to consider: Thayer's, Glaucous-winged, and Slaty-backed. Oh, and various hybrid combinations, of course, but we'll hold off on going there until and unless we rule out all good species. Herring Gull is readily eliminated from consideration due to our bird's relatively pale tail (even though all dark) and the relatively pale wingtips, among other notable features. Of our possible solution set of three species, Slaty-backed is the easiest to rule out, as that species usually has a darker wingtip and dark tips to the greater and median secondary coverts that form two very vague dark wing bars. Additionally, first-cycle Slaty-backeds usually have darker secondaries contrasting more strongly with the inner primaries.

Now, here's the really tricky part, differentiating Thayer's and Glaucous-winged gulls. Given appropriate circumstances, separation is fairly straightforward, as standing and swimming birds, particularly with good yardstick species present for comparison, are easy to differentiate on size, both overall and bill size. Here, we lack both -- the bird is flying and is the only gull present, and it's not even particularly close to the identifiable ducks to give us even a gross impression of gull size. Thus we have to use plumage characters, although I will say that, to me, this bird looks like it has a fairly broad wingbase, but I would in no way rely on that impression for the ID.


The single feature that is most likely to lead observers/respondents to consider Thayer's Gull for this quiz bird is probably the 'Venetian-blind effect' of the dark outer webs of the outer primaries contrasting with the paler inner webs. However, it is important to remember that first-cycle individuals of all large, white-headed gull species exhibit this contrast, with the species differing only in the degree of contrast which is governed mostly by how much of the inner web on a given feather is pale and how widely spread the wingtip is (thus, how much of the inner web is visible).

To my eye, the quiz bird's forehead is too sloped and the bill too big to be those of a Thayer's Gull, but, again, we have no good comparison individuals present. The eye seems to be 3/5 or more of the way back on the head from the bill tip (front of eye to bill tip, which I measured as 60.4%, with a very generous estimation of the location of the back of the head). This again suggests to me that the bird is not a Thayer's Gull, as the values of my sample of six Thayer's Gulls in pictures in Howell and Dunn (2007), birds in pictures 36.6, 36.8, 36.11, 36.12, and 36.13, ranged from 47.9% to 54.4%. Of course, this is a very gross measurement when conducted on birds not in the hand, so we should not have much confidence in the result. But, it does provide yet another weak structural cue to the bird's ID.

However, we don't have to rely on such characters, because there is at least one fairly strong plumage cue: The pattern of individual feathers in the scapulars and inner secondary coverts. On Thayer's Gull, these feathers are typically fringed with white, with the paler individuals having wider and more-extensive fringes; picture 36.8 in Howell and Dunn (2007) provides a good comparison of this feature in darker and lighter first-cycle Thayer's Gulls. One would imagine that this feature would be easy to mis-interpret, because one would expect the paler birds to show less contrast to the white fringes than would darker birds, perhaps making the pale fringes less obvious. But, in picture 36.8, the darker bird has considerably narrower and less-extensive white fringes than does the paler bird and, despite the lower fringe-ground color contrast, the paler bird still has more-obvious white fringing than does the darker bird. Since our quiz bird is in the paler half of the variation of first-cycle Thayer's Gull plumage darkness, we could expect this bird to have fairly substantial white fringes to these feathers. However, our quiz bird has what appears to be white tips or subterminal spots on the scapulars and inner secondary coverts (greaters, medians, and the lower lessers). This pattern is typical of Glaucous-winged Gull, three examples from the same locale in the same month (all on 12 November 2007) of which I've included below.



And here are three examples of first-cycle Thayer's Gull from the same locale and date.



The only sticking point for this bird being a Glaucous-winged Gull, is the darkness of the outer webs of the outer five primaries. While this feature might suggest some gene contribution from Western Gull or Herring Gull, my experience with the species from Washington to Sonora is that it is found in  a variable, but far from insignificant, percentage of individuals that look otherwise perfectly fine for Glaucous-winged Gull, even in older plumages. So, I do not see the need to invoke introgression, but, regardless, the bird is not a Thayer's Gull. I took this picture of a first-cycle Glaucous-winged Gull (one that serendipitously has a couple of identifiable ducks in it) at Lucchesi Park, Petaluma, Sonoma Co., CA, on 23 November 2007.



With the final quarterly competition and the annual competition coming to a close with this quiz, it is time to award a couple of prizes. For the quarterly, Richard Jeffers wound up with the most correct responses (nine). However, since he won the previous quarterly competition, he is ineligible to win this one, so we go to the five respondents that each had eight correct responses to search for a winner. Those five were Tyler Bell, Ben Coulter, Donald Jones, Margie Joy, and Joshua Little. Congrats to all of them, but there can be only one winner. The first tie-breaker is the fewest number of incorrect responses, and one of the five had only one of  those. Joshua Little wins the fourth quarterly competition of the year, winning a year's membership in Colorado Field Ornithologists, thus receiving the great journal, Colorado Birds.


In the annual competition, the winner had the title clinched a few quizzes ago, as Ben Coulter's closest competition had 39 correct responses to Ben's 43. Ben wins a waived registration fee for the 2013 Colorado Field Ornithologists' convention in the southwestern corner of the state in Cortez! The convention will be an excellent venue, providing access to a great variety of bird (and other) species, with some southwestern Colorado specialties being of prime interest, particularly the only known breeding areas in the state for Lucy's Warbler (McElmo Canyon) and Acorn Woodpecker (Durango).

Incorrect species provided as answers:
Thayer's Gull - 11
American Dipper - 1
Horned Grebe - 2
Blue-winged Teal - 1
Bufflehead - 1

Unfortunately, 0 of 15 respondents got the quiz correct, but with most of those getting the two duck species correct.

Answer: Mallard, Ruddy Duck, Glaucous-winged Gull


Monday, December 10, 2012

Quiz #478 (2012-4-10) Solution

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Solution by Tony Leukering

This week's quiz bird has fairly wide-based wings and a wide and distinctly buff-and-black-banded tail; quite an interesting combination. We can also see some vague darkish streaking on the chest that fades into the belly and the whitish vent. The wide-based wings rule out the commonest day-flying ABA-area species with a tail pattern like that, Northern Harrier. As there are no other kites, hawks, etc. with such a tail pattern and such wide-based wings, we'll have to look elsewhere. We don't have to go very far, foraging-style-wise, to get to the owls, which, as a group, tend toward wide-based wings. This bird's tail pattern is not quite right for Burrowing Owl, nor is that contrastingly pale orange-buff patch in the wingtip. Great Horned Owl, which comes in a bewildering array of colors and patterns can also be eliminated on that contrasting wing patch and on the unmarked palenss of the lower belly and vent. The only reasonable options remaining are the two 'eared' owls, a duo that is not known at all well by most birders.

Differentiating Long-eared Owl from Short-eared Owl in flight can be very tricky, but we have some fairly good lighting and a reasonably good view, two features that are not all that common when viewing Asio owls. Both sport the contrasting paler wingtip patch of our quiz bird, but Long-eared is only rarely (if ever) colored this warmly buff, particularly the tail. Long-eared Owls also have darker streaking below that extends farther south, so would be quite visible, given this view. Finally, Long-eared has that wing patch tend more toward rufous than our quiz bird's orange-buff. Steve Mlodinow took this picture of a Short-eared Owl in October 2011 at Port Susan Bay, Snohomish Co., Washington.

Incorrect species provided as answers:
Merlin - 1

Congratulations to the 16 of 17 getting the quiz correct:
Pam Myers
Tyler Bell
Ben Coulter
Joshua Little
Nick Komar
Logan Kahle
Margaret Smith
Donald Jones
Peter Wilkinson
Patty McKelvey
Margie Joy
Richard Jeffers
Kirk Huffstater
Sean Walters
Joe Bens
Bryan Guarente

Answer: Short-eared Owl

Monday, December 3, 2012

Quiz #477 (2012-4-09) Solution

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Solution by Tony Leukering

I know the quiz picture is tricky when the number of incorrect species provided as answers approaches the number of correct responses, and this quiz is an excellent example of such. The six incorrect species are of six genera in four families in three orders.

The size of the bird in the image is purposefully quite small in order to eliminate small-scale features visible. That is because most birds are not seen well enough in the field to discern such features, particularly this species. From the wave action, we can make the assumption that the water body is large, which should have us keeping pelagic species in the back, at least, of our minds.

The tubby body and large, rounded head rule out a large number of waterbird options, including some of those ruled out by other features. These other features include the bird's small feet and gray sides, which eliminate loons from consideration. Those same gray sides rule out various petrels and a number of the alcids, including murres, murrelets, and puffins. The unpatterned wings rule out most ducks. Looking closely at the head, we can see two critical features:  the white eye and the pale base to the bill (see expanded version of photo quiz, below).
 Among ducks, only Surf Scoter has whitish eyes and unpatterned wings, but only in males, and this is obviously not a male Surf Scoter. In fact, that bird's pale eye now reduces the options to just a few species of auklets. The gray sides, again, help here, as they rule out Least Auklet. The quiz bird's bill is too substantial to be that of Whiskered Auklet, while Crested Auklet is eliminated form the possible solution set by the extensive amount of what appears to be whitish plumage. Parakeet Auklet is ruled out by the lack of a white behind-the-eye eyeline. That pale base to the bill makes for positive (rather than negative, like the eyeline) determination for us. I took this picture of a Cassin's Auklet off San Diego, San Diego Co., CA, on 8 October 2011.

Incorrect species provided as answers:
Fea's Petrel - 1
Harlequin Duck - 1
Ancient Murrelet - 1
Black Scoter - 1
Pacific Loon - 1
Parakeet Auklet - 1

Congratulations to the 6 of 12 getting the quiz correct:
Logan Kahle
Ben Coulter
Tyler Bell
Donald Jones
Joshua Little
Richard Jeffers

Answer: Cassin's Auklet

Monday, November 26, 2012

Quiz #476 (2012-4-08) Solution

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Solution by Tony Leukering

Excellent! No one stumbled over the hyphenation/non-hyphenation problem, the primary reason that I used this picture in the quiz. Two respondents figured out that reason and provided a bit of humor in their responses.

Peter Wilkinson: Why can't you just call it French Heron, and then we wouldn't have to worry about hyphenation and spelling and all that?!
Joshua Little: To dash or not to dash? Not to dash.

This week's quiz bird is a heron and the blue wings, brownish back, and white belly fooled no one into mis-stepping on the ID, at least among the respondents. I took this picture of a Tricolored Heron on 27 January 2010 at the Viera wetlands, Brevard Co., FL.

Incorrect species provided as answers:
none -- excellent!

Congratulations to the 21 of 21 getting the quiz correct:
Kirk Huffstater
Ben Coulter
Logan Kahle
Tyler Bell
George Cresswell
Su Snyder
Pam Myers
Margaret Smith
Gary Koehn
Peter Wilkinson
William von Herff
Donald Jones
Patty McKelvey
Margie Joy
Richard Jeffers
Joshua Little
Casey Ryan
Anji Trujillo
Joe Bens
Bryan Guarente
Nick Komar

Answer: Tricolored Heron

Monday, November 19, 2012

Quiz #475 (2012-4-07) Solution

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Solution by Tony Leukering

Ah, another tricky swallow/swift thing. The upperparts are unrelieved brown. While we cannot see much of the underparts at all, the throat is quite pale. First, we'll tackle the swift/swallow dichotomy. The wide-based wings with a fairly wide arm (part of wing from base to wrist) is wrong for swifts, particularly Chimney and Vaux's, which have very narrow-based wings and short arms.

Once we're among the swallows, we can quickly rule out all but the "brown" swallows: Northern Rough-winged, Tree, and Bank (this bird does not have the heft of a martin, such as Brown-chested). Unfortunately, we cannot see the tail shape well, but there's at least the suggestion of a notch or fork, though I'd be leery of depending upon that mark from this tricky view, so we'll keep Northern Rough-winged in the mix for now. The striking aspects of the bird to me are the very dark wings and the rump being the palest part of the upperparts plumage. Northern Rough-winged Swallow is typically unicolored -- or very nearly so -- above, particularly with brown flight feathers, not blackish ones. Tree Swallow shows an obvious indentation of whitish behind the wing on the flank that is lacking in our quiz bird. Other features supporting the ID as Bank Swallow include the very narrowly-pointed wings, narrow back end of the body, and pale fringes to the uppertail coverts. In my experience, from above, Bank Swallow's color is palest on the rump and gradually gets darker in all directions. I have another picture of this individual Bank Swallow on my Flickr site, which I took at Big Johnson Res., El Paso Co., CO, on 1 June 2011.

Incorrect species provided as answers:
Northern Rough-winged Swallow - 11
Chimney Swift - 3
Tree Swallow - 3
Purple Martin - 1

Congratulations to the 1 of 20 getting the quiz correct:
Joshua Little

Answer: Bank Swallow

Monday, November 12, 2012

Quiz #474 (2012-4-06) Solution

 
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Solution by Margie Joy and Tony Leukering

A pile of swallows perched on wires, this is obviously a quiz photo that demands careful scrutiny. When we study such birds, many know to look at tail shape, among other features. However, many birders do not particularly notice that the various ABA-area species of swallows are of differing size, such that in congregations as this, one can often note a smaller or larger species among a horde of other swallows. Though I intended to write a lengthy piece, Margie Joy provided a succinct solution, so I'll start there.

"The perched birds appear to be Purple Martins in various plumages. I see several all-dark adult males, gray adult females, pale-bellied juveniles, and heavily spotted first-summer males. All seem the same size and most show the forked tail of Purple Martin.

"I first thought that the smaller, flying bird was behind the martins but, on looking closer, is actually in front. It shows the long, narrow, curved wings and bullet-shaped body of a swift. My best guess is Chimney Swift because of the mostly dark color and narrow wings. It's difficult to see marks on this bird but the throat appears to be a bit paler than the top of the head, but not as contrasty as Vaux's or White-throated swifts, and it doesn't seem as dark overall as Black Swift would be."

Indeed, Margie has dealt with this one nicely. While there are a couple of birds that look smaller or that sport a pale forehead, none of the perched birds are actually smaller, and all for which we can see the tail shape have the deeply-notched tails of Purple Martin. I have included, below, a cut-out of the swift for your ogling pleasure. I took this picture of massing Purple Martins and a flying Chimney Swift from my roof in Villas, Cape May Co., NJ, on 13 August 2011.




It is interesting that the names of all three of the correct respondents have a 'j' in them; the first two are the only respondents with perfect 6-for-6 scores in the current quarterly competition.

Twelve respondents provided answers that included no incorrect species but just one correct species, Purple Martin.

Incorrect species provided as answers:
Northern Rough-winged Swallow - 2
Cliff Swallow - 1

Congratulations to the 3 of 18 getting the quiz correct:
Margie Joy
Richard Jeffers
Joe Bens

Answer: Chimney Swift, Purple Martin

Monday, November 5, 2012

Quiz #473 (2012-4-05) Solution

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Solution by William von Herff and Tony Leukering

William von Herff provided a good solution, so I'll start with that.

"Well, here we have a bird clinging parallel to the trunk of a tree. We can see the tail, therefore we can assume that the bird is facing up. The only two families of ABA-area birds that cling vertically to trees are the creepers and woodpeckers. Brown creeper can be eliminated because it has a mottled brownish back, while this bird has a distinctly unpatterned black back, so it is a woodpecker. Now, it's time to start dissecting the field marks!

"First of all, the underside of this bird is mostly off-white. That eliminates most ABA-area woodpeckers; in fact, all except Red-headed, Golden-fronted, Red-bellied, Gila, Hairy, and Downy. Now, there is the black back with a big patch of white. The "solid black" part eliminates all of the options except Red-headed. But does that match up with the white patch? Well, Red-headed has a big white patch on the secondaries, so that matches."

Thanks, William. I will just add a few confirmatory points and discuss the bird's age. This quiz photo is an excellent illustration of the importance of using as many features in a bird's ID as one can manage. While sapsuckers also sport large white wing patches, they do not have mostly whitish underparts. As noted by William, the large white wing patch is composed of secondaries; the white wing patches on other woodpeckers are of different placement: those of sapsuckers are composed of secondary coverts, while those of the 'Centurus' ladder-backed species and Acorn and White-headed woodpeckers are composed of primary coverts and/or bases of primaries. Also, looking closely at the near edge of this white patch, we can discern two short, parallel black bars (indicated by arrows on inset, below), which is all we need to determine the bird's age as a first-cycle bird. Those faint bars on the bird's side adjacent to the white wing patch provides a feature confirming the bird's age.

I have also provided, below, the picture that I took of this individual before the one used as the quiz photo at Cox Hall Creek Wildlife Management Area, Cape May Co., NJ, on 8 January 2012. Note that those black bars in the wing patch are longer with the wing open. Also note, and this is very important when dealing with wing features, how the placement and shape of the white patch change from open wing to closed.

Incorrect species provided as answers:
Yellow-bellied Sapsucker - 3
Williamson's Sapsucker - 1

Congratulations to the 16 of 20 getting the quiz correct:
Tyler Bell
Bryan Guarente
Joshua Little
Ben Coulter
Kirk Huffstater
Robert McNab
Richard Jeffers
Gary Koehn
Donald Jones
William von Herff
Logan Kahle
Patty McKelvey
Su Snyder
Margie Joy
Casey Ryan
Joe Bens

Answer: Red-headed Woodpecker

Monday, October 29, 2012

Quiz #472 (2012-4-04) Solution


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Solution by Tony Leukering

[I apologize for the tardiness in getting the recent solutions posted, but I am currently catching up with a lot of writing projects after my return from Texas.]

Our backlit shorebird this week shows fairly strong contrast between white belly and brownish chest and a medium-length, perhaps droop-tipped, bill. These features may point some toward Pectoral Sandpiper. Unfortunately, anyone stopping analysis of the picture there would go astray, as the dark underwings and distinct black-and-white tail pattern certainly rule out that species. Yes, the underwings are actually dark; the underparts are shaded just as are the underparts and the white belly shows obvious and strong contrast with the dark
wings. Those features also rule out similar species, such as Sharp-tailed Sandpiper and Ruff. In fact, the dark underwings, alone, reduce our options to less than a handful: the two tattlers and Solitary and Wood sandpipers. The distinct tail pattern removes all but one of those.

I took this picture of a juvenile Solitary Sandpiper at Cape May Point S. P., Cape May Co., NJ, on 9 September 2011.

Incorrect species provided as answers:
Pectoral Sandpiper - 2
Wilson's Storm-Petrel - 1
Ruff - 2

Congratulations to the 15 of 20 respondents getting the quiz correct:
Margaret Smith
Donald Jones
Peter Wilkinson
Joshua Little
Ben Coulter
Tyler Bell
Pam Myers
Nathaniel Behl
Casey Ryan
Nick Komar
Robert McNab
Sean Walters
Margie Joy
Bryan Guarente
Richard Jeffers

Answer: Solitary Sandpiper

Monday, October 22, 2012

Quiz #471 (2012-4-03) Solution

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Solution by Tony Leukering

Ah, a pile of birds to sort through looking for different species. In the field, this flock might well be here and gone, allowing us little leisure at picking out any oddballs. But in this venue, we have a week to sort through the flock. But first, what is the primary component of the flock?

Near the bottom of the flock, we can see the top side of one bird with its wings fully extended. That bird has the brown head and back, black mask, gray wings, and yellow tail tip of a Cedar Waxwing. Quick perusal of the flock finds that there are no demonstrably larger birds, nor obviously grayer birds, thus there seem to be no Bohemian Waxwings here. All of the birds that are bullets (wings folded) have the same shape: angled head, deep belly, and medium-length tail. Finches have larger and rounder heads and most have shorter tails. Pipits have more-streamlined bodies. Bobolinks have more-pointed wingtips. In fact, no bird present strongly exhibits any feature that might suggest some other species. I took this picture of a flock of Cedar Waxwings at Cape May Point S. P., Cape May Co., NJ, on 2 October 2011.

Two respondents submitted answers with the species name as a plural. I have written previously that species names are not plural and should not be presented as plural. Though some might consider this simply semantics, there is a difference between answers that identify the birds and those that present what species is/are present. Despite the fact that there are 30 birds in the picture, there is only one species represented. I let those two responses slide and considered them correct, but please read the rules.

Incorrect species provided as answers:
Red Crossbill - 1

Congratulations to the 19 of 20 getting the quiz correct:
Tyler Bell
Ben Coulter
Robert McNab
Bryan Guarente
Patty McKelvey
Joshua Little
Marc Chelemer
Kirk Huffstater
Richard Jeffers
Su Snyder
Donald Jones
Nick Komar
George Cresswell
Peter Wilkinson
Casey Ryan
Margie Joy
Sean Walters
Pam Myers
Joe Bens

Answer: Cedar Waxwing

Monday, October 15, 2012

Quiz #470 (2012-4-02) Solution

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Solution by Tony Leukering

[I apologize for the tardiness in getting the recent solutions posted, but I am currently working in Texas away from Internet access, so I'm getting to them as I can.]

A black waterbird with greenish legs and white in the undertail coverts leaves us just two options, Fulica americana and Gallinula galeata. Were the head raised, this one would be a no-brainer, but we cannot see the bird's bill, so must use other cues to come to the correct ID. While the bird's head looks distinctly blacker than the rest of the dark plumage, the quiz bird also sports the white side stripe and whitish vent area typical of the latter of our two options. The primary reason for running this quiz pic, though, was terminological, not, as my friend, Glen, might say, identificational. I am just a wee bit surprised that I received no answers of "Common Moorhen." Considering the fairly recent split of Common Moorhen into an Old World species (Common Moorhen) and a New World species (Common Gallinule), I am pleased with the respondents this week.

Larry Semo took this picture of a Commmon Gallinule at Wakulla Springs State Park, Wakulla Co., FL, on 27 January 2011. Larry, I still miss ya, scamp.

Incorrect species provided as answers:
American Coot - 1

Congratulations to the 17 of 18 respondents getting the quiz correct:
Pam Myers
Tyler Bell
Patty McKelvey
Kirk Huffstater
Margaret Smith
Peter Wilkinson
Donald Jones
Joshua Little
Su Snyder
Ben Coulter
Logan Kahle
Robert McNab
Nick Komar
Richard Jeffers
Bryan Guarente
Margie Joy
Joe Bens

Answer: Common Gallinule

Tuesday, October 9, 2012

Quiz #469 (2012-4-01) Solution


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Solution by Tony Leukering

[I apologize for the tardiness in getting the recent solutions posted, but I am currently working in Texas away from Internet access, so I'm getting to them as I can.]

This quiz bird's tail shape takes us to the square-tailed doves, as we can eliminate pigeons from consideration by the extensive white tail tip. Thus, our choices are Eurasian Collared-Dove, White-winged Dove, Spotted Dove, and White-tipped Dove. Spotted Dove can be quickly eliminated by that species' tawny-pink underparts. White-tipped Dove is a shorter, squatter bird with a very short tail, unlike that of our quiz bird. Differentiating Eurasian Collared-Dove and White-winged Dove is an under-appreciated ID problem, in my opinion, hence this quiz.

Eurasian Collared-Dove's tail pattern is well-known as an ID point, but some often forget that it is useful in differentiating it from African Collared-Dove. However, its tail pattern is surprisingly similar to that of White-winged Dove: blackish base, extensive white tip. Additionally, in certain postures, White-winged Dove can appear to have Eurasian Collared-Dove's black extension down the outer web of the outermost tail feather. But, our quiz bird's blue facial skin and orange iris confirm it as a White-winged Dove. The apparent Eurasian Collared-Dove tail pattern is created by the bird's right r5 (fifth rectrix on right) peeking out from behind its right r6. I took this picture of a White-winged Dove in Pueblo, Pueblo Co., CO, on 25 January 2012.

Incorrect species provided as answers:
Eurasian Collared-Dove - 1

Congratulations to the 18 of 19 getting the quiz correct:
Pam Myers
Nick Komar
Debbie Barnes
Ben Coulter
Tyler Bell
Robert McNab
Margaret Smith
Donald Jones
Logan Kahle
Su Snyder
Gary Koehn
Kirk Huffstater
Richard Jeffers
Margie Joy
Peter Wilkinson
Joe Bens
Bryan Guarente
Sean Walters

Answer: White-winged Dove

Monday, September 24, 2012

Quiz #468 (2012-3-13) Solution

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Solution by Tony Leukering

Even the crew of regular respondents that have won quarterly competitions had problems with this quiz of two streaky sparrows or sparrow-like birds.  Careful scrutiny of the two birds, particularly the left one, should set off our alarm bells, as these seem to have the loose, fluffy plumage so typical of juveniles, which can certainly throw off our estimation of specific ID, as all bets are often off with juvs. Since nearly everyone got the right bird correct, we'll start there. This substantial bird, both long and quite chunky, rules out all of the skinny sparrows (e.g., Spizella species). Additionally, the very thick bill rules out a lot of the other options. The buffy-white wing patch, which occupies much of the greater coverts and quite a bit of the median coverts, is a particularly good clue. In combination with the bird's large size (relative to the other quiz bird), we really should entertain the possibility of Lark Bunting, Colorado's state bird. In fact, the head pattern looks quite good for that species, but the thin underparts streaking is not a feature that most of us think of on the species. But, this is, indeed, a juvenile, wearing juvenal (=first basic) plumage, and the thin streaking is typical of the plumage.
Now, for the left bird, which caused no end of consternation, with seven species provided as possible solutions to its ID. It, too, is a juvenile and, given the short availability of the plumage for ogling, most of us don't know juvenal sparrows at all well. Looking at the tail, we might note the suggestion of a whitish edge, though that could simply be an artifact of the picture. The head pattern is not distinct enough for most Spizella sparrows, but too distinct for Field Sparrow, which sports a very dull and plain head. However, the key feature is the bird's strongly rufous greater coverts, a feature of few sparrow or sparrow-like species:  McCown's and Lapland longspurs; Bachman's, American Tree, Vesper, Henslow's, Seaside, Song, and Swamp sparrows; and some Savannah and Fox sparrows. Some species -- Lapand Longspur and Bachman's, American Tree, Henslow's, and Seaside sparrows -- can probably be ruled out just on the unlikelihood of finding a fresh juvenal perched on a barbed-wire fence with a juvenal Lark Bunting. Remember, with very few exceptions, juvenal plumage is typically held for a very short time and only a couple of species can be found migrating in the plumage. We are left with the McCown's Longspur and Vesper, Song, and Swamp sparrows. We can rule out the longspur on toenail length -- they're called longspurs for a reason, as the nail on our bird's hind toe is not even as long as the rest of the toe. Additionally, our bird is too streaky below for a McCown's juvenile. Our bird's head pattern is too dull and the underparts aren't streaked heavily enough for either of the Melospiza sparrows and the bird is not streaky enough for a juvenile Savannah.  Fox Sparrow would be larger than Lark Bunting. Steve Mlodinow took this picture of juvenile Vesper Sparrow and juvenile Lark Bunting on Pawnee National Grassland, Weld Co., CO, in early August 2011.

Two respondents provided answers with just one species.

As this is the final quiz of the third quarter's competition, it is time to award the prize of a year's membership in Colorado Field Ornithologists. Five respondents ended the quarter tied with 11 correct responses: Ben Coulter, Richard Jeffers, Logan Kahle, Robert McNab, and Sean Walters. The first tie-breaker is the number of incorrect answers, and Richard wins via that one, with just one incorrect response. Congratulations, Richard!

As for the annual competition, Ben Coulter has a one-quiz lead on Robert McNab (35 to 34) for that honor.

Incorrect species provided as answers:
Grasshopper Sparrow - 3
Cassin's Sparrow - 1
Lark Sparrow - 1
Savannah Sparrow - 1
McCown's Longspur - 1
Savannah Sparrow - 1
Field Sparrow - 1

Congratulations to the 2 of 13 getting the quiz correct:
Logan Kahle
Joe Bens

Answer: Vesper Sparrow, Lark Bunting

Monday, September 17, 2012

Quiz #467 (2012-3-12) Solution

Click on picture(s) for a larger view.

Solution by Tony Leukering

We've got two birds this week apparently attacking thistle heads for sustenance. Just that fact could send us straight to the cardueline finches, which are so fond of thistles. But, let's do things thoroughly. The tiny piece of bill of the upper bird does not give us much with which to work to identify the family to which our quiz birds belong, but that bill tip does not look particularly thin. However, the very blackness of the wings of both birds, the lack of streaking throughout, and the very long primary projection really rule out all warbler options. Since our birds are quite small, there aren't many other options, as vireos are ruled out by the lack of any distinct head pattern, so we'll head to the back end of the field guide to figure out which finch.

The birds' size, overall plumage color, and lack of streaking limit us, really, to just three options: Lesser and American goldfinches and Common Chaffinch. Lesser Goldfinch can be ruled out by the combination of very black wings and bright white vent region. The dullest of Lessers can have white vent regions, but those are young females, which sport fairly brown wings. That is, males of these species have obviously black wings, while females tend to have dull blackish or brown wings that do not contrast so strongly with the white wing bars. Additionally, any black-winged Lesser Goldfinch should show much more white at the base of the primaries and most such birds would have yellowish vents. The same wing features that rule out Lesser Goldfinch also rule out Common Chaffinch, with males sporting an almost triangular lower wing bar with a connection of white to the upper wing bar. Females, which have browner wings, also tend to have the upper wing bar more yellowish and also tend toward a thin, but distinct dark postocular stripe. I took this picture of two male American Goldfinches at Pueblo Reservoir, Pueblo Co., CO, on 18 December 2004.

One respondent's otherwise correct answer included an incorrect assessment of sex directly with the species guess, thus was considered incorrect; please read the rules about this facet.

Incorrect species provided as answers:
Common Chaffinch - 1
Lesser Goldfinch - 1

Congratulations to the 17 of 20 respondents getting the quiz correct:
Tyler Bell
Patty McKelvey
Robert McNab
Ben Coulter
Kirk Huffstater
Richard Jeffers
Bryan Guarente
George Cresswell
Logan Kahle
Nick Komar
William von Herff
Su Snyder
Pam Myers
Joe Bens
Chishun Kwong
Margaret Smith
Sean Walters

Answer: American Goldfinch


Monday, September 10, 2012

Quiz #466 (2012-3-11) Solution

Click on picture(s) for a larger view.


Solution by Tony Leukering

[I apologize for the tardiness in getting the recent solutions posted, but I am currently working in Texas away from Internet access, so I'm getting to them as I can.]

This week's quiz was unanimously thought to be a raptor, perhaps at least in part due to the apparently hooked bill. With our bird's dipped-in-ink wingtips, pale underwings and underparts, and longish tail, we have few choices that fit. Swainson's Hawk might be considered, but adults have the secondaries entirely dark below, while youngsters -- which have less-black secondaries -- sport blackish streaking on the underparts, not reddish barring. Ferruginous Hawk might offer a safe haven, the bird does appear to have a wrist comma, but there is just too much black in the primaries and secondaries. The wings are too long and narrow for any accipiter.

In fact, the black wingtip is well outside the pattern for all but one ABA-area species: Northern Harrier. That black wingtip also allows us to sex the bird as a male and age it as an adult, as females and all juveniles lack black wingtips. While some/many/most might think that the reddish barring and apparently brownish inner wing on the top side may suggest immaturity, I am not convinced. Virtually every time that I get really good looks at black-wing-tipped harriers, they show at least some barring underneath and some brown on the back. So, unless I am being followed around by second-year male Northern Harriers, I suspect that most fully adult males show some of this. I agree that it may well be likely that younger males are more likely to show such markings and to show them more extensively, but I feel that Northern Harrier is quite different from what is considered by the AOU to be the Old World subspecies and called by Brits, Hen Harrier, adult males of which are generally clean white underneath and clean gray above.

One correct respondent's answer included a guess as to sex directly in the answer. Had that guess been incorrect, I would have had to have marked the response as incorrect (please read the rules). I took this picture of an adult male Northern Harrier at Cape May Point S. P., Cape May Co., NJ, on 22 October 2010.

Incorrect species provided as answers:
Swainson's Hawk - 1

Congratulations to the 20 of 21 getting the quiz correct:
Tyler Bell
Peter Wilkinson
Robert McNab
Ben Coulter
George Cresswell
Richard Jeffers
Logan Kahle
Kirk Huffstater
Su Snyder
Thomas Hall
Margaret Smith
Al Guarente
Margie Joy
Pam Myers
Maureen Briggs
Nathaniel Behl
Chishun Kwong
Bryan Guarente
Joe Bens
Sean Walters

Answer: Northern Harrier

Monday, September 3, 2012

Quiz #465 (2012-3-10) Solution

Click on picture(s) for a larger view.
The picture was taken in June in both species' breeding habitat.

Solution by Tony Leukering

The true take-home message for me concerning this quiz photo was that respondents did not make full use of the hint/caveat. If you are coming to this quiz blind, you might want to ponder that red-text note carefully.

Our quiz's focus bird is yelling about something, perhaps the bird on the tree on which it's about to land. What? A shorebird landing in a tree? Certainly, some species do it quite a bit, such as the species in question, though generally only during the breeding season and when on territory. Many of us have seen those pictures of Hudsonian Godwits standing on the tops of Black Spruces in their breeding haunts (and if you're like me, have been really keen to see such for yourself!), so we might consider that species; the tree IS a conifer! Our bird also certainly has black wing linings. However, Hudwits lack our bird's dusky-tipped white tail and the second white band on the underside of the wing. That leaves us with only Willet as an option, and all of the other features visible are consistent with that ID.

Now, we just have to solve the second bird. The combo of cinnamon coloration below and blackish wings does not leave us many options, particularly with that longish dark bill and that we know that the picture was taken in June (see caveat, above). That means that this must be a female of one of what I call the "big boy" grackles, Boat-tailed and Great-tailed. Yes, even female Rusty Blackbirds are never this uniformly cinnamon, and they certainly are not so in June. On breeding habitat.  They are black.  Or blackish.

Knowing the other species is a Willet might give us cause to think that the solution is easy, but Willet breeds next to both species of large grackle over its odd range. But, that range is the important factor here, as the Atlantic and Gulf Coast breeders (the ones that share range with Boat-tailed Grackle) are referable to what is termed "Eastern Willet," while those in the western part of North America (and which breed in places that also support Great-tailed Grackle), are "Western Willets." They are currently considered subspecies of one species, but they have obviously traversed quite some distance down the road to species differentiation, as they are readily separable on voice, plumage, and size cues. So, all we have to do to ID the grackle is determine to which subspecies the Willet belongs.

Western Willet is larger than is Eastern Willet, but that character is not so useful here. However, it is also paler and grayer and less-heavily marked below in alternate plumage than is Eastern. Our Willet's heavily barred brown chest and sides point straight at Eastern Willet.

I took this picture of a complaining (Eastern) Willet and a female Boat-tailed Grackle near Rio Grande, Cape May Co., NJ, on 5 June 2012. One respondent's otherwise incorrect answer had Willet mis-spelled and another's included "Eastern" in the species' name, which is incorrect.

With three quizzes to go in the quarterly competition, four are tied at the top of the leader board with nine correct: Ben Coulter, Richard Jeffers, Robert McNab, and Sean Walters.

Incorrect species provided as answers:
Rusty Blackbird - 7
Seaside Sparrow - 1
Sage Thrasher - 1
"Avocet" - 1
Eastern Willet - 1
Eastern Bluebird - 1
Townsend's Solitaire - 1
Bendire's Thrasher - 1

Congratulations to the 6 of 19 respondents getting the quiz correct:
Ben Coulter
Margie Joy
Robert McNab
Su Snyder
Pam Myers
Sean Walters


Answer: Willet, Boat-tailed Grackle

Monday, August 27, 2012

Quiz #464 (2012-3-09) Solution

Click on picture(s) for a larger view.
The picture was taken in February.

Solution by Tony Leukering


White geese and not-so-white geese, that is the question. Whether 'tis nobler in the field to suffer the slings and arrows of the lack of Ross's Goose from ones state/province/county/yard list or to take pen in hand and tick it off, and by so marking, end them.

With apologies to The Bard, we begin this week's attempt to avoid the slings and arrows of the CFO Photo Quiz by choosing yea or nay on the presence of Ross's Goose in this field (and it was truly a field) of Snow Geese. The very first thing to recall is that juvenile Snow Geese are easy, as long as one has ruled out hybrid geese and youngster Greater White-fronteds. That is because juvenile Ross's Geese are nearly all white, with just some darker smudgy bits here and there. The bird so comically looking into the camera is a first-year Snow Goose with most of its juvenal plumage intact -- it is basically brownish-gray (or grayish-brown, if you prefer), with those fancy, long, black-bordered, white scapulars hanging down. Most of the other geese in the picture are also first-cycle Snows in various states of transition from juvenal to adult-like colors. We can even see the large grin patch (the dark flattened oval at the meeting of mandible and maxilla) on the beak on the head sticking into the bottom of the frame, which is a key feature in differentiating Snow and Ross's geese. Since all but one of the truly white geese are completely facing away and out of focus -- and are, thus, unreliably identified, we should probably concentrate our hopes and dreams for our state/province/county/yard list on the adult white goose in the right of the frame. It is only mostly facing away, but, perhaps, something might be done with the bird's bill to give us a clue; it certainly looks at least somewhat smaller than the young Snow Geese between it and us. The angle, though, may preclude any confidence in assigning a name to the beast, as it is really impossible to be certain of the bird's bill's shape, though it does look a bit long and slender to be the bill of a Ross's Goose. In the end, unless provided a better view, we are better off leaving it as unidentified, even if we assume that it is a Snow Goose.

Had all of us known that the field in question is in the Skagit, Washington, area, in February, we could be fairly certain that our assumption that all geese in the picture are Snow Geese would be correct, because this area supports all (or virtually all) of the Siberian-breeding Snow Geese during winter. Because Ross's Goose does not breed in Siberia, instead would arrive locally from a somewhat mirror direction, records of the species in the area are exceedingly few. I took this picture of a mass of Siberian Snow Geese on 5 February 2006. There were at least 3 Siberian neck collars on geese close to the road; who knows how many more there were amongst the masses. Thanks to Cameron Cox for escorting me here and explaining about these geese.

Incorrect species provided as answers:
Snow x Ross's Goose - 1
Ross's Goose - 1

Congratulations to the 14 of 16 getting the quiz correct:
Ben Coulter
Margaret Smith
Patty McKelvey
Robert McNab
Nick Komar
Margie Joy
Pam Myers
Jim Nowjack
Richard Jeffers
Kirk Huffstater
Peter Wilkinson
Bryan Guarente
Sean Walters
Logan Kahle

Answer: Snow Goose

Monday, August 20, 2012

Quiz #463 (2012-3-08) Solution

Click on picture(s) for a larger view.

Solution by Tony Leukering

Ah, a nice, bright, red bird, well-lit and in focus. While we could certainly wish that that bird's head would be turned just a bit more our way, there really is no doubt that this is a male Northern Cardinal. End of story. For that bird, at least. There is a second bird in the picture that requires a bit more work and care. Much of that bird is hidden behind the male Northern Cardinal -- and the red bird looks roughly similar in size, perhaps a bit smaller, but we can see that the entire upperparts are a medium gray, that the tertials have white tips or fringes, and that the tail is long and blackish. Unfortunately, most of our ABA-area options with such upperparts and tertials sport white on the tail, which just does not appear in our quiz picture. Well, this iteration of the CFO Photo Quiz is all about structure and posture. So, let's get on with it.

Species that we might consider include both gray shrikes (although, why is the Northern Cardinal right next to something that would be more than happy to eat it?!), Townsend's Solitaire, Northern Mockingbird, Phainopepla, and Pine Grosbeak. First, recall the placement of the individual tail feathers when the tail is folded. From the topside on a completely folded tail, we can see only the two central rectrices (r1 on each side), while from underneath, most of what we can see is the pair of outermost rectrices (r6 on each side). So, since we're looking at the bird from above, as it were, even if it had extensive white on the outer rectrices, we would probably not see it on this tightly folded tail. So, that tail neither rules out the array of species with white on the tail, nor rules in Phainopepla or Pine Grosbeak.

We are not left with much to go on, but the primary reason for using this picture is all about leg length. You see, of the six options, only one of them has long legs, Northern Mockingbird. In the below image cut out from the quiz photo, I have arrows pointing to various legs in the picture (NOCA=Northern Cardinal, NOMO=Northern Mockingbird); note that the gray bird's left leg is mostly hidden behind the red bird's right leg.


In such a picture of any of the other candidate species, we would see nowhere near as much leg and, in fact, Townsend's Solitaires often show almost no leg at all, their legs are so short. Finally, I have inserted, below, another picture taken of this duo just seconds later; the image is not much different, but does provide more evidence for an ID of Northern Mockingbird that was present along the shores of Lily Lake, Cape May Point, Cape May Co., NJ, on 16 April 2012.


Note: I could swear that when I first looked at responses early last week that one respondent had noted leg length as a major ID point, and I was going to congratulate that person. However, I cannot find such now. Ah, well, it's heck getting old!

Three respondents provided answers with only one species, all Northern Cardinal.

Incorrect species provided as answers:
Plumbeous Vireo - 1
Townsend's Solitaire - 1

Congratulations to the 17 of 22 respondents getting the quiz correct:
Tyler Bell
Jeff Witters
Robert McNab
Ben Coulter
Christian Nunes
Nick Komar
Richard Jeffers
Margie Joy
Logan Kahle
Al Guarente
Margaret Smith
Su Snyder
Peter Wilkinson
Bryan Guarente
Kirk Huffstater
Joe Bens
Sean Walters

Answer: Northern Mockingbird, Northern Cardinal

Monday, August 13, 2012

Quiz #462 (2012-3-07) Solution

Click on picture(s) for a larger view.

Solution by Tony Leukering

This week's quiz bird seems to be perched on rip rap, and since there seems to be water behind it, we might surmise that the bird is on a jetty. Of course, that assumption may or may not help us with the bird's ID; it might even send us astray. Regardless, since we can see at least one of the bird's hind toes and it is not elevated, we can rule out any shorebird. In fact, our bird appears to have a stout and short bill, dark above and yellowish below. Those features, also, rule out shorebirds, as do its short, pink legs.

The short and stout bill might send us to the back of the field guide where reside most such ABA-area birds. The plain and dull underparts, in combination with the pink legs, rule out all of the finches. The brown crown and those pink legs might then send us searching among the Emberizidae (the New World sparrows and similar things), but that plain and dingy breast doesn't fit too many options there. The brown towhees are, well, too brown, and the beastie just looks off for it to be any of the plain-breasted sparrows, perhaps because of those blackish bits on the chin and throat. Ah, that lovely, Canadian breeding endemic sparrow, Harris's, has black on the chin and throat, but it should have either a lot more black in that area (adults), or less (immatures), and, if less, ought to have some black spotting/streaking on the upper sides, which it lacks. Even though, to experienced birders, it might seem unlikely, I have seen multiple beginning birders identify those brown birds with black on chin and throat nesting in the eaves of their houses as Harris's Sparrows. That may be because they get to the New World sparrows in the field guide, find Harris's Sparrow, and stop looking. Thus, they don't find, at the very back of the book, that introduced sparrow from the Old World that also sports black chin and throat (and upper breast). While our bird does not sport much of the black typical of a male House Sparrow, we can see the rough outline of that black and be happy with that ID. What we may not know, though, is that male House Sparrows molt in new feathers on the chin, throat, and upper breast in late summer/fall (along with all of their other feathers) that have thin to wide pale fringes that obscure the black throat patch. As those feathers wear through the fall and winter, the black becomes more and more evident.

Those that studied the quiz bird more closely will have noticed that the crown looks at least partly brown, not entirely gray, and that there does not appear to be any black in front of the eyes. Ah, close scrutiny is always good when obtainable. When male House Sparrows grow their juvenal (=first basic) plumage in the nest, they grow female-like plumage. However, once fledged for a bit, they initiate their preformative molt and bring in obviously male plumage. With these facts, we can safely surmise that our quiz bird is an immature male House Sparrow somewhere in the process of replacing its juvenal plumage in its first fall, when I took the picture at Avalon, Cape May Co., NJ, on 7 October 2008. I have included, below, an enlarged crop of our quiz bird's upper body in which one can see the mix of dull, even pale, brown and gray feathering in the crown; the former being juvenal feathering, the latter adult. Amazingly, the location of the photograph was guessed by one respondent, Sean Fitzgerald. Of course, he had an unfair advantage, having spent an entire fall standing by this jetty counting the immense southward migration of waterbirds there, oddly enough, in 2008! Finally, at least as this quiz is concerned, Peter Wilkinson correctly sussed the bird's plumage and which molt it was conducting.

Now that we're a bit over halfway through the quarter's competition, Richard Witters finds himself alone atop the leader board with a perfect 7-of-7 score; seven others are on his heels with 6 correct responses. As for the annual competition, Ben Coulter (30 correct responses) has a one-correct-response lead on Robert McNab.

Incorrect species provided as answers:
none -- excellent!

Congratulations to the 21 of 21 getting the quiz correct:
Logan Kahle
Tyler Bell
Ben Coulter
Jeff Witters
Sean Fitzgerald
Margaret Smith
Nick Komar
Richard Jeffers
Chris Witt
Bryan Guarente
Larry Griffin
Al Guarente
Jim Nelson
Robert McNab
Su Snyder
Peter Wilkinson
Margie Joy
Pam Myers
Sean Walters
William von Herff
Joe Bens

Answer: House Sparrow

Monday, August 6, 2012

Quiz #461 (2012-3-06) Solution

Click on picture(s) for a larger view.

Solution by William von Herff and Tony Leukering

It was obvious to respondents that this week's quiz bird was a juvenile accipiter, and as is often the case with this genus, answers ran the gamut of possibilities. Quiz newcomer William von Herff provided an excellent analysis of the bird, so I'll start with his take and finish up with some minor additional notes. William?

"Ah, a perching accipiter! And a headless one at that! Oh joy! Anyway, you can get to accipiter because of the slim size, the streaks on the underside, and the barred tail. As well, the streaks mean that it's a juvenile.

"So, now we have to differentiate the three accipiters. Well, it's a juvenile, and you can notice that it has what appears to be a clean vent and undertail coverts. Northern Goshawk would have scattered teardrop-shaped splotches on the vent and undertail coverts and a much more broken and scattered under tail pattern, compared to that of the quiz bird.

"So, on to the Sharpie/Cooper's duo. Normally, we could just look at the head structure from this close up, but this bird is hiding its head shape, so we have to figure it out using other clues. So, let's look over some key ID points. The most well-known juvenile accipiter separator is the streaking: Cooper's has thin streaks that fade away around the belly area, while Sharpie has thicker streaks that go farther down. The quiz bird has thin streaks that fade away at the belly area, so this points to Cooper's. The trait is highly variable, though, so I'll give Cooper's 0.75 points (Sharpie: 0 Cooper's: 0.75). The second feature is shape: Cooper's has a very barrel-shaped chest, while Sharpie has a body shape that gets thinner as it goes down. The quiz bird, while it is at an awkward angle, looks very barrel-shaped. (Sharpie: 0 Cooper's: 1.75). Third of all, leg thickness: Cooper's have fairly thick legs, while Sharpies have pencil-thin legs. This bird seems to have thicker legs, so I'd give another point to Cooper's. (Sharpie: 0 Cooper's: 2.75). Next, there's the terminal band: This is very variable, so whichever gets this one, gets only a half-point. Cooper's has a fairly wide terminal band, while Sharpie has an extremely thin terminal band. The quiz bird seems to have a wide terminal band, so Cooper's gets a half-point (Sharpie: 0 Cooper's: 3.25). Then, there's the tail length: This is a very awkward angle, so I'm going to compare it to the length of the wing. On Sharpie, the wingtip ends at the end of the second band from the body, while in Cooper's, it ends at the very start of that band. In this bird, the wing ends at the start of that band, so another point for Cooper's. (Sharpie: 0 Cooper's: 4.25). Finally, tail shape: Cooper's tends to have a rounded tail, while Sharpie has a straight tail tip with two sharp corners. This bird seems to have a tail leaning more toward Sharpie, so a point for Sharpie. (Final score: Sharpie: 1 Cooper's: 4.25). Now, this duo has plenty of variation in every single aspect that I just mentioned, so that's why I thought it would be better to tally up the field marks, instead of doing elimination ID."

Thanks, William! Some other points that I wished to make on this one are that juvenile Northern Goshawk have very thin white bands bordering the dark tail bands that contrast paler both with the obviously dark bands, but also with the wide pale bands. My last comment is that I would probably have given Cooper's the whole point for tail shape because, though the tail is mostly squared-off, we can see the outermost right rectrix (it is misplaced to the middle of the tail) and it is obviously shorter and lacking a distinct corner at the outer edge of the tip (instead, the outer part of the tip is quite rounded). This is a feature that is diagnostic in differentiating Cooper's Hawk from Sharp-shinned Hawk. Steve Mlodinow took this picture of a juvenile Cooper's Hawk at the Shillapoo Wildlife Area, Douglas Co., Washington, in January 2011.

Incorrect species provided as answers:
Sharp-shinned Hawk - 2
Northern Goshawk - 1

Congratulations to the 17 of 20 respondents getting the quiz correct:
Tyler Bell
Al Guarente
Logan Kahle
Ben Coulter
George Cresswell
Su Snyder
Richard Jeffers
William von Herff
Bryan Guarente
Robert McNab
Margaret Smith
Josh Yoder
Peter Wilkinson
Nick Komar
Pam Myers
Joe Bens
Sean Walters

Answer: Cooper's Hawk

Monday, July 30, 2012

Quiz #460 (2012-3-05) Solution

Click on picture(s) for a larger view.
The picture is not of an ABA Code 5 species.

Solution by Tony Leukering

What's a day when one doesn't learn something? I like to avoid such days and, thanks to Peter Wilkinson, I have avoided that pitfall today.

This week's quiz bird is obviously a small gull (plumage and small, dark bill) and the caveat with the quiz photo precluded Gray-hooded Gull from being the solution. Once amongst the small gulls, we should check wingtip pattern to greatly reduce the number of options. In this view, we cannot see much of anything of the wingtip pattern, but we can see enough. The enough of which I write is the underside of the outermost primary (p10) on both wings and on both wings, those feathers are nearly entirely white. That means that this cannot be other than one of the species with white wedges in the wingtip. (As an aside, studying the underside of the wingtips in most gulls can be quite useful in arriving at an ID and one can usually manage such on a perched or swimming gull.)

Differentiating Black-headed and Bonaparte's gulls can be a mite tricky at times, but this view is not one in which it should be, and I note that no respondent went with Black-headed, though some missed the obvious separator. Bill color is often useful in discerning between the two species, dark reddish in the former, black in the latter. However, this color can be tricky to assess in some pictures and I would certainly be hesitant to rule out Black-headed on the strength of bill color on this picture! Throw in the difficulty in assessing mantle color (Black-headed's is paler than is that of Bonaparte's) and I would have been left with a single -- though excellent -- differentiating character. Our bird's nape is obviously gray; Black-headed sports a white nape (and crown) contrasting with the gray mantle.

This is where that new knowledge bit comes in. Peter Wilkinson pointed out that there is another clue, in the shape of the meeting of black tip and white body of p10 in the two species. Bonaparte's shows a smoothly curved meeting extending from the inner margin of the feather down toward the tip and to the outer margin of the feather (as on the quiz bird; see inset, below). With Peter's suggestion, I looked into the feature a bit and found that the meeting in Black-headed is rather straighter, cutting across the feather or, even, slightly back up the feather, such that where the white meets black on the inner margin is at the same distance from the tip -- or closer -- than where it meets on the outer margin. As Peter noted, I doubt that the character would be useful in the field, except under the most beneficial circumstances, but it seems to be readily assessable in photographs given an appropriate view.

I took this picture of an adult Bonaparte's Gull in North Cape May, Cape May Co., NJ, on 11 March 2010.

One respondent's answer was precluded from being correct for the competition as it neglected the "e" in the name of the species and another's was precluded as the "g" went uncapitalized.

Incorrect species provided as answers:
Ross's Gull - 1
Black-legged Kittiwake - 1

Congratulations to the 18 of 20 getting the quiz correct:
Ben Coulter
George Cresswell
Nick Komar
Logan Kahle
Tyler Bell
Margaret Smith
Robert McNab
Jim Nowjack
Al Guarente
Richard Jeffers
Josh Yoder
Su Snyder
Margie Joy
William von Herff
Peter Wilkinson
Kirk Huffstater
Bryan Guarente
Sean Walters

Answer: Bonaparte's Gull

Monday, July 23, 2012

Quiz #459 (2012-3-04) Solution

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Solution by Tony Leukering

A long, somewhat-lanky raptor dashes over a pond in front of two ducks. While the ducks may not have drawn much attention, they also did not confuse many of us. As is typical, the raptor did.

I will start down the solution road with the two ducks in the background. They appear to be quite similar to each other in size and shape, so might very well represent a single species. We can see the right bird's tail, which is mostly white. As we know from previous quizzes at this venue, a white tail in dabbling ducks (note the patterned body feathers that rule out virtually all diving ducks) means either Mallard or Northern Shoveler. The bill color would rule out all but the youngest juvenile Mallards (which do have black bills), but the yellow eyes rule out even that option. In fact, these three features leave us only Northern Shoveler as an option and the combination of bright yellow eyes and black bills indicate that both birds are adult males, despite their drab dress. The extensiveness of the white in the tail of the right bird also points in that direction.

The raptor is brown with paler underparts; a yellow eye; a relatively hooded look; and a longish, banded tail. Not knowing the actual distance from raptor to ducks, we cannot truly assess the raptor's size in relation to the known Northern Shovelers. However, those with a knowledge of photography will probably guess that, due to the fact that both the ducks and the raptor are in focus (or nearly so), that they are not all that far apart. That could mean that the raptor is not insubstantial, but let's try to back that assessment up with confirmatory features in order to truly rule out Sharp-shinned Hawk. Well, Sharpies only rarely show the strong hooded aspect shown by our quiz bird and features of the bird's head also support ruling out the smallest of ABA-area accipiters: the eye is placed far forward on the head and is small relative to head size; the crown is flattish with a long-sloped forehead. Additionally, the head is certainly protruding well beyond the leading edge of the wings. Finally, the tail just looks too long to be that of a Sharp-shinned Hawk.

The longish tail and its pattern rule out nearly all other non-accipiter options (as does eye color for a few), so we're left with Northern Harrier and the two large accipiters. Brown Northern Harriers have long, banded tails like that of our quiz bird, but the dark and light bands are of nearly equal width. Also, the quiz bird sports only the barest suggestion of the pale, median-covert bar sported by brown Northern Harriers.

We are now left with just the two big accipiters. Juvenile Northern Goshawks show white highlights to the dark bands on the tail and also sport wing bars created by pale bases to both the median and greater coverts and thin, white tips to the greater coverts; our quiz bird lacks all of these and does not sport the obvious pale superciliary of Northern Goshawk. While the presence of such a super would not rule out Cooper's Hawk, the lack certainly rules out Northern Goshawk.

I took this picture of a juvenile female Cooper's Hawk flying over Bunker Pond in front of two adult male Northern Shovelers in "non-breeding" plumage at Cape May Point State Park, Cape May Co., NJ, on 22 October 2011. I note here that virtually every time that I have seen a raptor mis-identified as a Northern Harrier, the bird was a Cooper's Hawk -- the two species can be remarkably similar in appearance and shape.

One respondent's answer provided incorrect assessment of sex of the ducks directly with the species determination, thus the answer was precluded from being correct for the competition.

Incorrect species provided as answers:
Sharp-shinned Hawk - 2
Northern Harrier - 2
Blue-winged Teal - 1

Congratulations to the 14 of 20 respondents getting the quiz correct:
Tyler Bell
Robert McNab
Logan Kahle
Al Guarente
Ben Coulter
George Cresswell
Don Jones
Thomas Hall
Richard Jeffers
Kirk Huffstater
Margaret Smith
Josh Yoder
Bryan Guarente
Sean Walters

Answer: Northern Shoveler, Cooper's Hawk

Monday, July 16, 2012

Quiz #458 (2012-3-03) Solution

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Solution by Tony Leukering

A bird flies over your head flying away and you have scant time to assess the bird's features. Unfortunately, this is not a video clip, as flight style would help tremendously in winnowing the choices, but, alas, we are stuck with this static picture. We get a strong impression of a long, dark tail with an extensive white tip; whitish underparts; and a white trailing edge to the secondaries. These three cues leave few species to fill a possible solution set, which might include White-winged Dove, Northern Shrike, and Blue Jay.

Close scrutiny of the tail tip might allow us to determine that the white tip does not extend across all rectrices, as the central two are dark-tipped. Unfortunately, that does not reduce the number of options, as all three solution-set members have the same pattern. We might note that the central pair of tail feathers (rectrix 1 -- or r1 -- on each side of the tail) are slightly longer than the rest and protrude a wee bit beyond the tips of the adjacent pair (the r2s). This feature could be useful as long as we know that it's not due to some ephemeral posture that the bird was in when the picture was snapped. However, the tail tip does provide us another clue: each succeeding pair of rectrices from r2 to r6 has a more-extensive white tip than does the previous. White-winged Dove has, essentially, the same amount of white on each white-tipped feather. Finally, the white trailing edge to the secondaries is much more extensive than shown by any Northern Shrike.

I took this picture of a Blue Jay overhead at Cape May Point, Cape May Co., NJ, on 7 May 2011. Other clues that we might have used include the dark feet (ruling out doves) and, as noted by Thomas Hall, the bluish aspect to the upperside of the bird's right wing.

One respondent provided two different answers; I accepted the most-recent one as that person's official response; unfortunately, incorrect.

Incorrect species provided as answers:
Clark's Nutcracker - 1
Lark Sparrow - 1
White-winged Dove - 1
Eastern Kingbird - 1
Black-billed Magpie - 1

Congratulations to the 14 of 19 getting the quiz correct:
Ben Coulter
Tyler Bell
Richard Jeffers
Al Guarente
Margie Joy
Logan Kahle
Thomas Hall
Su Snyder
Pam Myers
Robert McNab
Bryan Guarente
Josh Yoder
Sean Walters
Chishun Kwong

Answer: Blue Jay

Monday, July 9, 2012

Quiz #457 (2012-3-02) Solution

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Solution by Tony Leukering

A relatively drab bird, and one that is apparently small (considering the comparison to the vegetation), is this week's quiz subject. The only strong bits of not-brownish coloration that we can see are in the tail and the wings, which is actually a solid clue about one aspect of the beast. The color in the tail on such a small bird leaves us only a few families to play with for the ID of the bird. Since we can see the bases of the secondaries and there is no dark bar there, we can rule out the kinglets (of course, the pink legs had already done for them) and Yellow-browed Warbler. The lack of a whitish lower wing bar and the bright yellow-green tail rules out Arctic Warbler (as do a few other features). These excisions from our possible solution set should leave us with just New World warblers and orioles, but we can scratch the latter, as any oriole even close to this small has obvious wing bars (our bird has only the barest suggestion of a tan lower wing bar).

Once among the New World warblers, we can eliminate whole scads of species on our bird's lack of wing bars. If we could see the lower part of the inner webs of one or more of the outer two to three pairs of rectrices, we would know whether the quiz bird has tail spots or not, which would help us tremendously. Unfortunately, the only rectrices of which we can see inner webs are the middle ones on the bird's left side; the outermost ones are stacked under those. However, those tail-spot-less middle rectrices do the job of ruling out the species with tail spots on those feathers that we might have considered, particularly Yellow and Hooded.

The bird's lack of any bright plumage on the head, back, chest, sides, and flanks should give us pause. Taking a closer look, we can see that there a few, scattered scapulars or wing coverts that appear to be colored like the secondaries, but most are dull tannish-brown. Hmm. So, the bird must be molting in a brighter set of feathers, so the bird must be either a very worn adult or a recent fledgling. Looking at individual dull feathers in that same region, we can see that the feathers are not tightly barbed, but very loose, with long, stringy filaments at their tips. This is a feature typical of juvenal (=first basic) plumage in many species, particularly passerines.

Aha! That could certainly explain the dull coloration, coloration that really fits nothing in the various guides, because, juvenal plumage is given exceedingly short shrift in most field guides, at least of passerines. At this point, it might be politic of me to remind readers that warblers in first basic (=juvenal) plumage have the flight feathers (primaries, secondaries, rectrices) that they're going to wear for nearly a year and which sport adult-like colors and patterns. Thus, we are able to use these feathers to determine the identity of our quiz bird.

Because of the color of the flight feathers that we can see, we may have reduced our solution set to those mostly unpatterned yellowy-green species, such as (in no particular order) MacGillivray's, Mourning, Kentucky, Connecticut, Wilson's, Orange-crowned, and Nashville warblers, and Gray-crowned and Common yellowthroats. Though we might have considered Tennessee, that species sports very thin bills and, as youngsters, has bright lemony wing bars. Bill shape rules out Gray-crowned Yellowthroat (too thin), Wilson's Warbler (too long and thick), and Orange-crowned and Nashville warblers (too thick and blunt).

Though we may think that we have nowhere to go from here, short of having a field guide that included all of those ephemeral passerine juvenal plumages, we actually have two good clues. The first one is that the tail looks fairly long, which, if true, would rule out all but one species left in our possible solution set. The other is absolute, but unknown by most birders because it's not a field mark that one is going to be able to use in the field all that often. However, thanks to the superb photograph by Steve Mlodinow (taken in western Washington in July 2010), we can actually discern that the bird has no rictal bristles, and only one regularly occurring ABA-area parulid meets that criterion and, most wonderfully, the species suggested is also the one suggested by our bird's long tail. (Rictal bristles are modified feathers at the base of the bill that lack barbs and are generally considered to assist with capture of small, mobile prey in the air; they are obvious on aerialist avian predators and shorter and less-obvious on species that do little fly-catching; on this Black Phoebe, note the bristles sticking out both above and below the bill.)

I provide, below, another picture of the same individual showing the incoming patch of yellow feathers on the chest of this young Common Yellowthroat molting into formative plumage. Though a majority of respondents submitted incorrect answers, a plurality got this quiz correct. After two difficult quizzes, only five respondents sit atop this quarter's leader board with perfect scores:  Richard Jeffers, Margie Joy, Pam Myers, Su Snyder, and Peter Wilkinson.

Incorrect species provided as answers:
Orchard Oriole - 4
Yellow Warbler - 3
Mourning Warbler - 4
Orange-crowned Warbler - 1
MacGillivray's Warbler - 1

Congratulations to the 8 of 21 respondents getting the quiz correct:
Robert McNab
Su Snyder
Richard Jeffers
Margie Joy
Nick Komar
Pam Myers
Thomas Hall
Peter Wilkinson


Answer: Common Yellowthroat

Monday, July 2, 2012

Quiz #456 (2012-3-01) Solution

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Solution by Tony Leukering and Sean Walters

All eight of this week's quiz birds are of very similar size and shape, so they must be of the same species or of incredibly similar species if there are multiple species present. Of course, since these are shorebirds, we know that there are certainly sets of very similar species, particularly in the small Calidris sandpipers (Semipalmated/Western/Red-necked/Little and White-rumped/Baird's). We could spend hours studying the picture and I could spend hours discoursing on why this species or that species is not included in this picture, but I think that I will take Sean Walters' tack to the correct answer. Sean wrote

"... only one Calidris species has a completely gray underwing. All of the birds have completely gray underwings, so they are all of the same species."

Good for you, Sean, particularly as that was the very reason that I used this photo, as all similar species have extensive amounts of white on the underwing. All eight birds are showing, to greater or lesser extent, their underwings, making the ID straightforward. I took this picture of Red Knots on 26 September 2011 at Stone Harbor Point, Cape May Co., NJ. Note: multiple respondents provided answers including more than one species, hence the disconnect between numbers of respondents and numbers of answers.

Incorrect species provided as answers:
White-rumped Sandpiper - 4
Western Sandpiper - 1
Baird's Sandpiper - 2
Semipalmated Sandpiper - 2
Sanderling - 1
Pectoral Sandpiper - 1

Congratulations to the 13 of 19 getting the quiz correct:
Al Guarente
Margaret Smith
Kirk Huffstater
Ben Coulter
Richard Jeffers
Margie Joy
Logan Kahle
Sean Walters
Su Snyder
Pam Myers
Peter Wilkinson
Josh Yoder
Bryan Guarente

Answer: Red Knot