Quiz #407 (2011-3-02) Solution

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Solution by Tony Leukering

What an odd-looking bird. The extreme patchiness and irregularity of the white bits suggest an abnomality of plumage in this week's quiz bird -- a good time to rely on our understanding of structure and posture! And, of course, the "good" field marks that we can see.

Before heading down the solution road, I want to state that this bird is not an albino, nor is it a "partial albino," which is an impossibility. For a fuller explanation of those terms and others, one might check out the 5 December 2010 post on the Cape May blog (you will have to scroll down to the date).

The bird is standing on the ground with head held a bit above horizontal. What isn't white on the head is black and the medium-length bill is a bright orange-yellow. The upper chest has some rusty or maroon color, as do the feathers on the upper leg. The non-white bits of the upperparts are all gray and what is not white in the tail looks black. The one leg that we can see is an odd, pasty bluish-white color, but the eye that we can see is dark. The bird has a fairly long primary projection (extension of the wingtip beyond the tip of the longest tertial) and the wingtip falls beyond the tips of the uppertail coverts -- so, a fairly long wing, particularly considering that the tail is not short.

The structure and posture point to a thrush of some sort, and the overall coloration (sans the white bits) sends us to the genus Turdus. While the bill looks orange enough to be that of Rufous-backed Robin, that species does not sport our quiz bird's black head or tail, and, obviously, has a rufous back. (As an aside, why did the AOU exempt only this species and American Robin from the recent change from "Robin" to "Thrush?" Rufous-backed Robin is not even the second-most common Turdus in the ABA area! Clay-colored Thrush is and it breeds in the ABA area!) Fieldfare does have a black tail, but also exhibits a gray head and brown back, and lacks rusty on the leg feathers. Redwing has grayish-brown upperparts (including head and tail) and lacks rusty on both the upper breast and the leg feathers.

So, nothing for it but to go with what was probably the obvious answer to most. Steve Mlodinow took this picture of a piebald American Robin at Drake Lake, Boulder Co., CO, in April 2011. I will leave to the reader to determine which form of leucism is expressed in this interesting bird (see cited blog, above).

One response lacked capitalization of "robin" and another included an incorrect guess as to the condition of the bird directly in the answer; both responses were precluded from being considered correct for the competition.

Incorrect species provided as answers:
none

Congratulations to the 22 of 22 getting the quiz correct:
Su Snyder
Tyler Bell
Thomas Hall
Robert McNab
Al Guarente
Bryan Guarente
Chuck Carlson
Pam Myers
Joel Such
George Cresswell
Marcel Such
Ali Iyoob
Peter Wilkinson
Julie Rouse
Margie Joy
Diane Porter
Margaret Smith
Chishun Kwong
Burke Angstman
jody1310 (Please provide your full name when submitting responses to the quiz)
Kirk Huffstater
Joe Bens

Answer: American Robin

Quiz #406 (2011-3-01) Solution

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Solution by Tony Leukering

While the lighting on this week's quiz subject might make for tricky analysis of color, there really is little other than black visible in the bird's plumage. With the strongly-fingered hands, this must be a large and soaring bird. The bird's head appears slightly paler in color than the plumage and much of the bill looks to be paler than the head, in addition to the bill looking fairly thin. Finally, the outer six primaries seem to be a bit paler than the rest of the wing plumage.

While ravens do soar, they never sport the number and length of fingers visible here. While Snail Kites have fairly round wings, they don't sport the very wide and squared-off wings of our quiz bird, nor does the species sport that many fingers. Additionally, if the quiz bird were of that species, the plumage would require the bird to be an adult male, which sports an orange-red bill. Hook-billed Kite does sport very rounded/square wingtips and does come in a dark morph, but the base of the bill is pale (rather than the tip) and it has pale eyes. Juvenile California Condors have nearly entirely dark plumage and paler heads, but the tip of the bill is the darkest part of the bill and the bill is thick.

The angle of light on our quiz bird, as noted above, is tricky, with the underside of the wing being entirely shadowed, with the sun above and to the bird's right and with the right wing nearly edge-on to the sun. This means that the extensively white outer six primaries don't show up as white as they might have had we been looking up at those wingtips with the light coming through them. So, regardless of whether or not there are those that disagree with my assessments in the previous paragraph, the fact that the bird's outer six primaries are noticeably paler than the rest of the wing plumage really leaves us only one ID option. I took this picture of an adult Black Vulture over West Cape May, Cape May Co., NJ, in spring 2011.

One respondent's answer was precluded from being correct for the competition, as a guess on age was included directly in the answer with the species name ("young Black Vulture"). As I can demonstrate with the head being paler than the body plumage and the bill mostly paler than the head that it is an adult.... Another respondent's species answer lacked all capitalization and punctuation, so even if correct, would have been precluded from being correct for the competition. PLEASE READ THE RULES.

Incorrect species provided as answers:
California Condor - 4
Golden Eagle- 1
Zone-tailed Hawk - 1
Turkey Vulture - 1
Common Raven - 1
Snail Kite - 1

Congratulations to the 8 of 17 getting the quiz correct:
Tyler Bell
Margie Joy
Ali Iyoob
Al Guarente
Robert McNab
Chishun Kwong
Diane Porter
Marcel Such

Answer: Black Vulture