Answer by Tony Leukering

We've got two birds to deal with this time, and they don't all that similar. Of course, that may be due to age or plumage differences, so we should tackle that aspect first. The strong white fringes to the tertials, some lower scaps, and a few coverts suggest that the bird on the left side of the picture is a juvenile, but that it has replaced numerous back, scap, and covert feathers with formative plumage. The bird on the right is much blander, with only a few scapulars and a tertial having the distinctive white fringe of juvenal plumage.

The left bird is more distinctive looking, with its black upper scapular and ulnar bars, dark crown, and dark brown shoulder bar. Add all those features to the thick-based, all-black bill and we have only one real choice: Sanderling. With that decision made, the second bird becomes easier to ID, as we have a solid direct comparison of size and various shapes. The second bird is somewhat smaller, with a thinner, longer, and droopier bill. As Sanderling is already a fairly small shorebird, we don't have a lot of options and since our bird is not a plover, we head to that angst-causing group, the peeps.

Despite the potential for difficulty, aspects mentioned above narrow our choices considerably. We can rule out the long-winged peeps, Baird's and White-rumped, as they would be more nearly the size of Sanderling than is our quiz bird. Though some Least Sandpipers have long, droopy bills, our bird's bill is probably longer than even the longest-billed Leasts. Additionally, Least Sandpipers are considerably browner, with a more-or-less obvious hood, lacking on our quiz bird.

The above leaves us with Semipalmated and Western sandpipers and two vagrant stints. Bill shape can immediatley rule out the stints. In basic plumage, the Semipalmated and Western sandpipers can be quite difficult to separate. As the Sanderling in the picture still has a significant amount of juvenal plumage remaining, the picture was probably taken during fall, and probably early in fall and, thus, probably in the ABA area. Our peep has very little remaining of its juvenal coat and that's one of the best hints that we have. Semipalmated, which winters outside of the ABA area, molts primarily on the winter grounds, though can initiate its pre-formative molt en route. However, finding a 1st-cycle Semi Sand with this little juvenal plumage remaining in the US in early fall would be virtually (if not completely) unheard of. Combine that with our bird's long, pointed, and droop-tipped bill, and we should have our answer.

I took this picture of Sanderling and Western Sandpiper, each in their first plumage cycle, at Stone Harbor Point, Cape May Co., NJ, on 23 September 2005.

Tallies of incorrect answers for quiz species:
Least Sandpiper - 2
Semipalmated Sandpiper - 1

Congratulations to:
The 35 of 38 respondents answering correctly:

Nick Komar
Mike Burrell
Su Snyder
Thomas Hall
Tyler Bell
Aaron Brees
John Bissell
Matthew Dodder
Tim Kalbach
Robert Hughes
Corey Husic
Chris Sloan
Chris Warren
Cory Gregory
Rachel Hopper
Andrew Dettling
Larry Griffin
Ira Sanders
Tammy Sanders
Wes Serafin
Ann McDonald
Peter Wilkinson
Saraiya Ruano
Lisa Edwards
Lisa Clements
Rick Clements
Harry Hooper
Patrick Belardo
Chishun Kwong
Matthew Schneider
Christian Nunes
Joe Bens
Joel Such
Marcel Such

Answer: Sanderling - Western Sandpiper