Monday, March 9, 2009

Quiz #290 (2009-1-11) Answer

Click the picture for a larger view.

Answer by Tony Leukering

Well, another bunch of flying dark birds. As in last week's picture, some of the birds look darker than others, that is, some are blackish, some are brownish. However, they appear to all be of a size and all with fairly short tails. Or, at least, not particularly long tails. The wings look unremarkable in length, with some showing quite pointed wingtips. Oh, and of course, "one of these things is not like the others."

In fact, we might want to identify the odd bird out, as it could greatly help us at nailing down the size of the rest of the birds. With that in mind, the gray coloration with a distinctly darker tail tip and obvious white rump really knock the number of possibilities way down. Additionally, the wide base to the tail should be helpful and is that a dark wingbar? Perhaps formed by dark tips or bases to the median or greater coverts? why, yes it is, and that combo of features leaves us with only one candidate -- thanks to the fact that none of this species' quite-similar congeners is on the ABA list. Yup, we're definitely looking, as may mother might say, at the south end of a Rock Pigeon going north. Now, while Rock Pigeon plumage is incredibly variable, the 'true' plumage of the species is much like our bird's, so we'll start on the other birds now.

Our other birds are considerably smaller, thus ruling out a lot of the dark options. Looking more closely at the birds to the left and above the Rock Pigeon after greatly enlarging the picture, we should see basically dark brown birds with a blacker aspect to the back with some sort of paler spotting or speckling or some such markings. And, indeed, the tails are fairly short and square and the wings are quite pointed. Hopefully, this sends us, like last week, to the bin marked
'winter-aspect European Starling.'

The possible blackbird choices, particularly Red-winged, have more rounded wingtips and relatively longer tails. A couple of the birds in the lower center part of the picture look overall darker, though that is due to those being nearly entirely shaded by others (note that many of the birds have anomalous darker patches that are the result of the same phenomenon). I have a sneaking suspicion that these are the birds that some identified as Brown-headed Cowbirds. However, that species is also slimmer than are European Starling, in addition to sporting more rounded wingtips and longer tails. The various swallow species would be notably smaller and slimmer relative to the Rock Pigeon, except, of course, for Purple Martin. That species can be eliminated by its notably notched tail. Additionally, none of the birds exhibits the typical contrastingly-reddish rump of Cliff (or Cave) Swallow.

I took this picture of a flock of basic-plumaged European Starlings and one Rock Pigeon (not Rock Dove!) in West Cape May, Cape May Co., NJ, on 3 January 2009.

At least two incorrect responses also provided 'Rock Dove' as one answer, which is not correct terminology (see the rules, please). One response was received about 6.5 hours after the deadline.

With two quizzes to go, and a quarterly competition with a large number of very difficult quizzes, we don't have any players with perfect (or close-to-perfect) scores. There are four tied at the top of the leader board with 8 correct: Tyler Bell, Aaron Brees, Andy Dettling, and Peter Wilkinson, with Tyler and Peter having a one-point lead in bonus points over Aaron (12-11). Four others are tied with 7 correct: Mark Gabriel, Bryan Guarente, Robert McNab, and Chris Warren.

Tallies of incorrect species provided in answers:

Northern Rough-winged Swallow - 3
Bank Swallow - 1
Red-winged Blackbird - 1
Brown-headed Cowbird - 3
Cliff Swallow - 2
Purple Martin - 1
American Robin - 1
House Finch - 1

The 12 of 24 providing the correct answer:

Tyler Bell
Peter Wilkinson
Al Guarente
Robert McNab
Chris Warren
Peter Burke
Mark Dettling
George Cresswell
Marcel Such
John Bissell
Joel Such
Bryan Guarente

Answer: European Starling and Rock Pigeon