Monday, September 14, 2009
Click the picture for a larger view.
Answer by Al Guarente and Tony Leukering
Every once in a while, I don't fully consider the photo that I put up as a quiz. Or, rather, I don't fully consider the total list of options for the species presented, and this was one of those times. I didn't really take into account the possibilities from south of the ABA area that are accidental within the ABA area. But, since Al Guarente dealt, briefly, with those, I'll start the solution with his answer. Go, Al.
"The larger bill and the forked tail lead me to the martins instead of the swallows [sensu stricto; sensu largo, martins are swallows]. I am considering only the females and young males here. I believe Cuban Martin is ruled out by the lack of brown on the throat and breast. The Brown-chested Martin looks similar to Bank Swallow, so we can rule that out. I believe the Southern Martin would be a lot dingier on the breast than the two birds pictured. That leaves me with Gray-breasted and Purple martins. Although I can't see the forehead on either bird very well, the bottom bird looks like it has a trace of white on the forehead, which leads to Purple Martin. The bottom bird also shows dark streaking on the breast (dark shafts) and the top bird has the dark, splotchy flanks which also lean toward Purple. So, I would have to guess this week's birds are Purple Martins."
I don't know that Al sufficiently ruled out the other "purple martins" from south of the ABA area, but as I received no such answers, I'll let things go. One of the subspecies of Brown-chested Martin does exhibit less of the Bank Swallow-like underparts pattern, but our upper bird's throat is too dark and the lower bird has none of that chest pattern, ruling that species out. Also, the tail is just too strongly notched for that species.
The dark throat on the upper bird combined with the purplish aspect to the upperparts rules out all of our swallows (again, sensu stricto) and the deeply-notched tail and dark shaft streaks on the underparts feathers of the lower bird do the same job. I photographed this adult female Purple Martin and one of her recently-fledged progeny at Villas WMA, Cape May Co., NJ, on 8 August 2009.
With one quiz remaining in the quarter's competition, Al Guarente clings to a one-quiz lead (with 11 correct) over Mark Dettling, Robert McNab, and Peter Wilkinson. Good luck to all on this week's quiz.
Incorrect species provided as answers:
Brown-chested Martin - 1
Northern Rough-winged Swallow - 1
Tree Swallow - 2
"Violet Green Tree Swallow" - 1
The 17 of 21 providing the correct answer:
Answer: Purple Martin