Quiz #353 (2010-2-11) Solution

Click on picture(s) for a larger view.
No ABA-area rarity is present in this picture.

Answer by Tony Leukering

I put this week's quiz picture up to talk about a specific field mark, primary coverts, that provide a great clue in separating a couple of similar species. The best plans of mice and men -- I wasn't counting on most of the incorrect answers being for an altogether different species. And now, I have to revamp the answer that I had written in my head.

All respondents got to the smaller gulls, probably due to the strong pattern of black and white on the upperparts, with the dark coloration in a vague 'W' pattern ('twould have been an 'M' pattern if the bird were heading away from us). With the red-phosphor caveat provided with the quiz picture, we don't have to worry about things like Gray-headed Gull, leaving us with just Bonaparte's and Black-headed gulls and Black-legged Kittiwake.

The field mark I had intended discussing, and still shall, is the color of the greater primary coverts. Though all birds have greater primary coverts (and, by extension, lesser primary coverts), there aren't that many groups for which the lessers are particularly visible in the field, so we tend to shorten things to simply primary coverts (covs). But, gulls are one of those groups that sport obvious lesser primary covs, hence the need for the modifier, 'greater.' This tract of feathers can be quite useful in separating immatures of Bonaparte's and Black-headed gulls, which can otherwise be quite tricky. Bonaparte's Gull sports a mix of black and white in those feathers, with the black much the more abundant on the outers and white more noticeable on the inners. By contrast, Black-headed immatures show nearly all-white greater primary covs.

While a number of respondents selected Black-legged Kittiwake as their answer, juveniles and immatures of that species have the entire leading edge of the hand (the wing from the wrist to tip) black or blackish, rather than the mix of black and white so obvious on our quiz bird. Particularly, note that the quiz bird's lesser primary covs are nearly entirely white, which would be a radical departure for a kittiwake. Also note that our bird's alula and outermost primary (p10) are also a mix of black and white, two feathers that are all black on young Black-legged Kittiwakes.

I photographed this immature Bonaparte's Gull at Villas, Cape May Co., NJ, on 22 April 2010. At this date, even immature Black-headed Gulls ought to be showing at least a hint of the adult bill color.

Incorrect species provided as answers:
Black-legged Kittiwake - 4
Black-headed Gull - 1

Congratulations to the 11 of 16 getting the quiz correct:
Robert McNab
Al Guarente
Thomas Hall
Kevin Kerr
George Cresswell
Su Snyder
Chris Warren
Peter Wilkinson
Bryan Guarente
Joel Such
Marcel Such

Answer: Bonaparte's Gull

Quiz #352 (2010-2-10) Solution

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

Answer by Tony Leukering

For the second week in a row, we have a poor, misunderstood adult Red-tailed Hawk being mobbed by some annoying, aggressive passerine! Perhaps interesting to you is that the individual hawk may very well be the same bird in the two quizzes! That is because this is one of the resident pair at the Villas WMA, Cape May Co., NJ, (here in early May 2010) and it rarely is able to make a pass over the area without attracting attention from those vicious passerines. Poor thing.

I know that I may have jumped the gun on identifying one of the birds in the quiz, but, hey, that's my prerogative as quizmeister. We can rule out Ferruginous Hawk, many of which can show at least something of a reddish tail, by the fact that our quiz bird lacks any obvious bit of wing panel (window), a feature that Ferruginous always shows and which only juvenile Red-tailed Hawks do.

The black bird may cause more problems. However, this quiz had something of a different focus than most others that I've conducted, as it was intended as a test of retention. That is, I wanted to see whether the regular respondents would remember the details of the solution for the last time that I ran a quiz crow. (Yes, we can rule out Common Raven by the bird's lack of a wedge-shaped tail and by its too-round wings. We can also rule out Northwestern and Tamaulipas crows by the caveat in red, above.)

Back in June 2009, I ran Mr. Bill Mystery Quiz #305. Many of the regulars that provided explanation of how they got to their answer this week noted that previous quiz. Unfortunately, some respondents did not, but most of those still got the this week's quiz correct. After perusing that previous quiz, one can see that this week's crow must be an American Crow, due to the obvious six fingers.

Incorrect species provided as answers:
Great Blue Heron - 1
Fish Crow - 3

Congratulations to the 12 of 15 getting the quiz correct:
Tyler Bell
Robert McNab
Claire Mix
Kevin Kerr
Nick Komar
Al Guarente
Joel Such
Margie Joy
Aaron Brees
Peter Wilkinson
Bryan Guarente
Chris Warren

Answer: Red-tailed Hawk, American Crow