Monday, November 30, 2009

Quiz #326 (2009-4-08) Answer

Click the picture for a larger view.

Answer by Tony Leukering

An obvious shorebird, with some important bits invisible: yet another typical Mr. Bill Mystery Quiz. The fuzziness of the picture might not help, either. A first task, after (of course) getting to shorebirds, might be to decide whether it's a larger one or a smaller one. As noted by a couple of respondents, the bird's proportions -- large, chunky body, thin neck, apparently smallish head -- should rule out the peeps (and isn't it nice to not have to deal with the Least Sandpiper/Long-toed Stint dichotomy!) and suggest a larger shorebird of some type. Though many birders would not even try to ID this bird in this posture, we've actually got a lot to go on and can quickly whittle things down to just a few options.

First, there aren't many larger shorebirds with such yellow legs and one of the usual large, buffy shorebirds that comes to mind, Marbled Godwit, is easily ruled out by the leg color. In fact, just utilizing leg color and overall color tone, we might consider only Pectoral, Sharp-tailed, Buff-breasted, and Stilt sandpipers; Ruff; and Wilson's Phalarope. We can quickly rule out Buff-breasted Sandpiper and Wilson's Phalarope, as those two species do not probe, but pick bits of food from the water's surface and/or land. Additional plumage features rule these two species out: lack of black spots at shoulder and dark-centered, rather than gray-centered, scapulars, among others.

Hopefully, no one would confuse our quiz bird with an adult Stilt Sandpiper, but some juvs can be this buffy and the species should be considered. Oops, we should already have considered age! The plethora of buff feather fringes should be all we need to decide that our bird is a juvenile, unless its a Ruff, as some adults sport such fringes, too. But, such birds would not have such a buffy throat and neck, so, regardless, our bird is a juvenile. At this point, we should, perhaps, throw Short-billed Dowitcher into the mix.

Returning to Stilt Sandpiper, even the buffiest-bodied juvs would sport white-fringed lower scapulars. Also, even with much of the bird's head in the water, we see enough of it to see that Stilt Sandpiper's obvious whitish superciliary is not present. Also, the legs have just too much orange aspect for that species. Despite tossing Short-billed Dowitcher into the mix in the previous paragraph, I'm going to quickly throw it back out, as our quiz bird lacks that species' whitish superciliary and would sport more and more-obvious internal markings on the scapulars and tertials.

Sharp-tailed Sandpiper should sport a quite-reddish crown and more-reddish feather fringes on the top side. Pectoral Sandpiper exhibits stronger blackish streaking on the throat and chest than does our quiz bird.

Whoa, lo and behold, we've eliminated all possibilities but one. Sean Fitzgerald took this week's quiz photo of a juvenile Ruff at Edwin B. Forsythe (Brigantine) N.W.R., Atlantic Co., NJ, on 8 October 2008.

One of the incorrect responses would have been considered precluded from being correct for the competition if it had been correct, as it included one too few hyphens and one too many capital letters.

Incorrect species provided as answers:
Sharp-tailed Sandpiper - 1
Buff-breasted Sandpiper - 2
Wilson's Phalarope - 2
Long-billed Dowitcher - 1
Stilt Sandpiper - 4

The 14 of 24 providing the correct answer:
John Bissell
Mark Dettling
Peter Wilkinson
Al Guarente
Peter Burke
Kevin Kerr
Nick Komar
Ira Sanders
Tammy Sanders
Marcel Such
Joe Bens
Tucker Lutter
Robert McNab
Joel Such

Answer: Ruff