Monday, November 12, 2012

Quiz #474 (2012-4-06) Solution

Click on picture(s) for a larger view.

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