Friday, December 26, 2008

Quiz #279 (2008-4-13) Answer

Answer by Tony Leukering

This week's quiz bird, with its strong side/flank streaking and large white tail spots is a warbler, and a Dendroica warbler at that. Yes, some other warblers have white tail spots, but none of those
have such obvious streaking on the underparts. The combination of side/flank streaking; unstreaked white undertail coverts; and large, white tail spots leave us with a few options, notably Cape May, Magnolia, Yellow-rumped, Black-throated Green, Townsend's, Black-throated Gray, Blackburnian, Yellow-throated, Grace's, Cerulean, and Blackpoll warblers. The ground color in the sides/flanks appears buffy-brown, not yellow, and that should do a tremendous job of whittling down the options to just three: Yellow-rumped, Yellow-throated, and Grace's.

Now, let's move to the tail pattern, a feature that many getting the wrong answer failed to fully consider. The pattern of the tail from underneath is an excellent ID feature that is, unfortunately, overlooked by most birders. Two guides treat this aspect of warbler anatomy well, The Sibley Guide and, particularly, the Peterson Warblers guide. In fact, the plates showing this feature in the Warblers guide are probably my favorite of all plates in all North American guides.

For those that may have objected to my wholesale removal of possibilities above may like to know that tail pattern does just about the same job for those species deleted from consideration as did side color. Magnolia Warbler has a white base to the tail and a wide, square-cut black tip; Cape May and Blackburnian warblers lack our quiz bird's black base to the tail, at least on the outer part. Our bird has a thin black base (which separates the white tail spots from the white undertail coverts), a wide white middle, and a thin black tip. Grace's Warblers and adult Yellow-throated warblers sport white bases to the tail and all ages of Yellow-throated have a white tail tip.

I took this picture of an immature, probably female, Yellow-rumped (Myrtle) Warbler on 22 October 2008 at Cape May Point S.P., Cape May Co., NJ. I provide, below, the picture taken of the bird immediately prior to the quiz picture.

Tyler Bell survived the carnage of the last two quizzes of the quarter to win the competition outright (with 11 of 13), beating Peter Wilkinson by one correct answer. Five others came in with nine of 13 correct. So, kudos to Tyler for winning this quarter's prize, a $25 gift certificate redeemable on the CFO website (!

As for the annual competition, of the 171 people that provided at least one answer this year, Chris Warren takes bragging honors and the $100 CFO website gift certificate, with 42 of 52 correct answers. Behind Chris, Christian Nunes beat out Aaron Brees (both with 39 correct) on the strength of the first tie-breaker -- total number of species correctly identified (which takes into account multi-species quiz pictures), 54 to 52, for second place. Interestingly, Rachel Hopper, our inveterate webmaster, got 36 correct and didn't play at all in the fourth quarter! Thanks, Rachel, for your interest in the quiz and for all of your hard work making the CFO website what it is!

Tallies of incorrect answers for quiz species:
Magnolia Warbler - 3
Black-throated Gray Warbler - 1
Cape May Warbler - 3
Blackburnian Warbler - 4
Sage Thrasher - 1
Northern Waterthrush - 1
Northern Mockingbird - 1
Eastern Bluebird - 1
Pine Warbler - 2
Townsend's Warbler - 1
American Pipit - 1
Cerulean Warbler - 1

For only the second time in my tenure as Mr. Bill, there were no correct answers submitted.

Answer: Yellow-rumped Warbler

Monday, December 15, 2008

Quiz #278 (2008-4-12) Answer

Click the picture for a larger view.

Answer by Tony Leukering

As all respondents noted, this week's quiz bird is obviously a white heron of some sort, facing directly toward the camera. However, note that I did not write 'into the camera,' as you'll notice that the bird's eyes are actually facing downward -- an interesting aspect of heron head morphology!

Our bird's strong yellow lores should rule out many possibilities, including the white form of Great Blue Heron (known as Great White Heron and possibly a good species), Little Blue Heron, and Reddish Egret. The fact that our bird seems to not sport either a black bill (it's just got a black tip) nor a yellow bill (it seems like a dirty pinkish to me) and with the suggestion of pink at the base of the bill on the bird's left side, I'd suggest that our bird is a juvenile that hasn't
achieved adult bill color, thus making any assessment of species using bill color at least a bit suspect. However, this angle should frighten anyone away from being at all certain of the actual bill color.

So, where should we look to pick one of the five species still on the possibilities list (Great, Snowy, Little, Intermediate, and Cattle egrets)? The apparently long and thin neck might go some way toward eliminating Cattle Egret, but I'm actually going to cut to the chase and go straight for the jugular... er... gape. Note that there is an extension of yellow from the lores well below the eye that seems to extend quite some way and, possibly, to nearly the back of the eye. Though gape length is something that many of us use to separate Ferruginous Hawk from other buteos, how many knew that one could ID this bird on that one feature?

I took this picture of a juvenile Great Egret on Bunker Pond, Cape May Point S.P., Cape May Co., NJ, on 26 October 2008. I provide below a picture that includes more of the individual.

Tallies of incorrect answers for quiz species:
Snowy Egret - 6
Cattle Egret - 1
Little Blue Heron - 2
Reddish Egret - 1

Congratulations to the 14 of 24 respondents answering correctly:
Jeff Jones
Larry Griffin
Tyler Bell
Victor Germain
Andrew Dettling
Kirk Huffstater
Chris Warren
George Cresswell
Thomas Hall
Joe Bens
Aaron Brees
Harry Hooper
Joel Such
Marcel Such

Answer: Great Egret

Monday, December 8, 2008

Quiz #277 (2008-4-11) Answer

Click the picture for a larger view.

Answer by Tony Leukering and Joel Such

Joel Such provided a good answer to this quiz, so we'll start there:

"This week's quiz bird looks like a diving duck. I can eliminate eiders, Harlequin Duck, Long-tailed Duck, scoters (except for Black Scoter), and alcids, because the quiz bird's wings are closed while diving. The aforementioned duck species all dive with their wings out and alcids dive with their wings out and their feet sticking out of the water. All the Bucephala ducks and the mergansers dive with their wings closed. The quiz bird has red legs, a black back, gray sides, white scapulars, white belly, some white vertical spots on the side, and a hint of rufous color toward the head. Those field marks match those of Red-breasted Merganser."

Joel probably noted my brief discussion for one of the ABA quizzes on diving style (; I'm glad someone is reading my answers and using the information. Additionally, just to round things out: LEG COLOR! I've noted this facet in this venue any number of times, but I don't know that I'm making any impression and leg color was quite useful in this week's quiz. Both goldeneyes have orange legs, while White-winged Scoter and Horned Grebe both have blackish legs. Those guessing Bufflehead might be excused a bit, as pink can be fairly similar to red, but on my monitor, the bird's leg is decidedly red, not the bubble-gum pink of Bufflehead. Besides, our bird has too much white in the wing for female-plumaged Buffleheads.

I took this picture of an actively diving adult male Red-breasted Merganser on 8 February 2008 at the Cape May ferry terminal, Cape May Co., NJ. Note that I called it an "adult male." Like other merganser species, Red-breasted Merganser exhibits delayed plumage maturation -- that is, males wear a female-like plumage for much of their first year and, in February, would still look mostly or completely like a female in plumage. I have provided, below, the picture that I took immediately prior to the quiz photo that shows the bird in all its glory.

With two quizzes to go in the quarterly competition, two out-of-staters, Tyler Bell and Peter Wilkinson (both with 10 of 11 correct), share the lead. Two Coloradans, Nick Komar and Christian Nunes (each with 9 of 11 correct), are breathing over the leaders' shoulders.

Tallies of incorrect answers for quiz species:
Common Goldeneye - 1
Horned Grebe - 1
Barrow's Goldeneye - 2
White-winged Scoter - 1
Bufflehead - 4

The 15 of 24 respondents answering correctly:
Thomas Hall
Fred Lesser
Andrew Dettling
Joel Such
Tyler Bell
Chris Warren
Peter wilkinson
Su Snyder
Christian Nunes
Linda Powers
Paul Hurtado
Joe Bens
Marcel Such
Andrew Spencer
Nick Komar

Answer: Red-breasted Merganser

Quiz #276 (2008-4-10) Answer

Answer by Tony Leukering

All respondents provided an answer including a falcon species, with most picking the correct one. The wing-open bird certainly has pointed wings and a raptorial beak. The only good candidates for such a beast with the heavy underparts streaking, regular rows of white spots on the remiges, and such a wide and dark subterminal tail band are American Kestrel and Merlin. However, neither sex of American Kestrel shows both heavy underparts streaking AND that wide subterminal band, so our bird must be a Merlin. In fact, it is an adult male taiga race (columbarius) Merlin that I photographed at the Cape May hawkwatch, Cape May Co., NJ, on 21 October 2008.

Now, onto the second bird.

"What second bird?" you might ask. Why, the bird that the Merlin is carrying. Most respondents (in fact, 22 of them) got the Merlin correct but did not provide an answer for the prey, so their responses were scored as incorrect (see the rules).

Merlins do often have a paler vent region, but it's never so white as what might appear to be that feather tract in the picture. That is because that white area is the underparts of a smaller bird in the grasp of our Merlin. We can see the head at the left end of the white patch, and the crown looks fairly green, metallic green. We can also see the unlucky second-subject-of-the-picture's wingtips (or, at least one of 'em) sticking below the Merlin's tail and the dark feet/legs against the white belly. The wings, then, are quite long if they're reaching near the end of what looks like a very short tail. If we look closely, we can see the area around the eye is blackish and obviously darker than the crown, without any paler area behind the eye. So, there are only two species recorded in the ABA area that have such long wings, a green crown, black mask, and white underparts from chin to undertail coverts, but one of them is an extreme ABA rarity (Mangrove Swallow), so our second bird is a Tree Swallow.

As I forgot to have Rachel (our webmaster) put the caveat on the photo at the outset, I would have accepted Mangrove Swallow as a correct answer, as I don't think that there is any way to rule out that species from this single picture. However, since only three respondents (of the 11 received before the caveat was put on the photo) provided answers including any swallow species, with only one of those incorrect and not of Mangrove Swallow, I feel that no adjustments in answers was necessary.

Tallies of incorrect answers for quiz species:
American Kestrel - 2
Cave Swallow - 1
Snow Bunting - 2

Congratulations to the 6 of 33 respondents answering correctly:
Christian Nunes
Tyler Bell
Andrew Spencer
Peter Wilkinson
Joe Bens
Chishun Kwong

Answer: Merlin, Tree Swallow

Tuesday, December 2, 2008

Quiz #275 (2008-4-09) Answer

Answer by Tony Leukering and Tyler Bell

The number of respondents this week was well down from typical, so I imagine that some number of folks were scared off by the gull wing. I don't blame 'em; this quiz was somewhat difficult. Tyler Bell provided an answer that dealt with many of the critical features and I'll use it below. However, I'm going to do things a bit differently this time and intersperse his comments (always in quotes) with mine, though some of my more editorial bits are enclosed in brackets within his quote.Thanks, Tyler.

"Lariphobia! So, what can we see with yet another partial bird?" The bird has a "white tail, so it is an adult, but the [outer] primaries aren't fully emerged,yet, which could trick one into thinking that it's something else."

The secondaries contrast darkly with the white wing lining, so our bird must be reasonably dark-mantled, say at Least Lesser Black-backed in coloration; paler-mantled gulls would show much paler secondaries that would not contrast like those of our quiz bird. Also note that the white tips to the secondaries occupy well less than the distal half of those feathers, a feature that can be critical in identifying darker-mantled gulls.

"The critical primary, p10 [the outermost; which is only half-grown] has extensive white on the distal portion, with only a small black spot near the tip."

Most white-headed gull species show a white tip to p10 that is separated from the p10 mirror by a black strap. All that exists of our bird's p10 strap is that single small black spot. As Tyler noted, this is a critical feature.

"The bird's p9 has a good deal of white on it as well."

That is, p9 has a white tip and a wide, black strap, but also has a sizable mirror (the vaguely leaning-snowman-shaped white patch distal to the tip of p10). Looking back at the secondaries, note that the white trailing edge is broken near the base of the wing -- that is probably a result of one or two of the innermost secondaries not being full-grown, yet. That will not come into play
in identifying the bird, but it does fit well with the fact that the outermost primaries are still growing -- in most birds, those are the last flight feathers to complete in the pre-basic molt. I point it out, though, because the tertials typically grow in before the innermost secondaries so that when Tyler notes that...

"... there's also a thin tertial crescent..."

... we can be sure that those inner white-tipped remiges are the tertials because of that very gap. The width of the tertical crescent, which is made up of the white tips to the longest tertials, is a feature useful in identifying white-headed gulls, with individual species having either thin or wide tertial crescents and all species with wide tertial crescents also having wide white tips to the secondaries and thin-crescented species having thin white tips to the secondaries.

"Hopefully, these details add up to Great Black-backed Gull!"

And, of course, Tyler is correct. The dark-mantled Pacific-Rim gull species (Slaty-backed, Western, and Yellow-footed) all have wide tertial crescents, wide white tips to the secondaries that occupy at least half of the length of the visible parts of the secondaries, and typically sport a complete strap on p10. Lesser Black-backed Gull has an even thinner tertial crescent than does Great Black-backed Gull, and an even smaller p10 mirror, which means a wider p10 strap. It also has a smaller p9 mirror than does our quiz bird. California Gull has more extensive black on each of the outer four primaries such that nearly the whole feather is black, unlike on our mystery bird, which has black on only the distal fifth or so of each p8 and p7; this creates the much larger black wingtip so typical of that species.

I have included the whole picture of the bird (below), which I took on 22 October 2008 at Cape May Point, Cape May Co., NJ. In the picture we can see an additional character useful in identifying the bird: its dull flesh-colored feet that no other adult large white-headed gull has.

One answer was received on Monday morning, after the deadline.

Tallies of incorrect answers for quiz species:
Ring-billed Gull - 1
Osprey - 1
Western Gull - 1
Mew Gull - 1
Lesser Black-backed Gull - 4
California Gull - 1
Herring Gull - 4

The 8 of 21 respondents answering correctly:

Tyler Bell
Ann McDonald
Christian Nunes
Peter Wilkinson
Matthew Schneider
Aaron Brees
Andrew Spencer
Nick Komar

Answer: Great Black-backed Gull

Sunday, November 23, 2008

Quiz #274 (2008-4-08) Answer

Answer by Tony Leukering

Well, another interesting week, with an interesting array of answers provided. Particularly interesting was that a single feature, leg color, rules out most of the incorrect species guessed. Yes, many of us use leg color in identifying some birds, but I am continually amazed how often that facet is ignored in most other identifications of unknown birds.

The combination of pale legs, grayish-brown lower back, heavily-marked undertail coverts and flanks, white vent region, and strong tan fringes to the greater coverts and tertials really does not leave us all that many options. In fact, it leaves only one. And then, if we peer over the bird's right tertials, we can see the lowest bit of a tawny brace.

As soon as I saw this bird foraging on Pitch Pine cones (along with a number of flock mates), I knew that it would make a great photo quiz, as at least some would think that the cones were critical to the bird's ID, when, in fact, they were a red herring. Below, I have provided another picture of the bird showing more completely its distinctive back pattern.

I took these pictures of a female House Sparrow at the Avalon seawatch, Cape May Co., NJ, on 2 November 2008. So, that's now the fourth time that I have used the species in an online photo quiz. I do such because to identify unknown birds, its often quite helpful to really know the ID of common birds cold.

One respondent's answer was discarded, as it arrived on Tuesday, a day-and-a-half beyond the deadline.

Tallies of incorrect answers for quiz species:
Golden-crowned Kinglet - 1
Snow Bunting - 1
Pine Siskin - 2
White-throated Sparrow - 1
Clay-colored Sparrow - 2
Harris's Sparrow - 1
Sage Sparrow - 1
White-breasted Nuthatch - 1
American Goldfinch - 1
Red Crossbill - 1
Ruby-crowned Kinglet - 1

Congratulations to the 13 of 26 respondents answering correctly:

Cory Gregory
Christian Nunes
Andrew Spencer
Nick Komar
Jeff Birek
Eric Zorawowicz
Chishun Kwong
Bryan Guarente
Victor Germain
Peter Wilkinson
Joe Bens
Marcel Such
Joel Such

Answer: House Sparrow