Shorebird ID Challenge

If you were to ask almost any North American birder which group or groups of species are the toughest to identify, shorebirds, in particular small Calidris sandpipers, would likely be near the top of their list. This genus includes birds that range in size from the largest, Great Knot, which is about 11" in length, to the smallest, Least Sandpiper and Little Stint, which are about 6" in length. The latter two are among a group of similar small waders that we collectively refer to as "peeps" in North America (called "stints" elsewhere in the world); all are between six and seven inches long. While all of these species may be found in homogeneous flocks, it is more typical to see them mixed together, sometimes with a few slightly larger members of the Calidris genus, on the same expanse of mud. 

Speaking of mud, we hope this exercise leaves you with an understanding of shorebird ID that is clearer than that substrate. We've chosen a photo that offers a sampling of the expected Calidris sandpipers (no Asian strays) that occur in the U.S. There are only six birds in the picture, which you can study at length in the privacy of your own home. Ideally, the ID tips and clues that are shared here will help you the next time you come face-to-face with a flock of shorebirds. After all, there is no substitute for seeing these birds in life and for most of us the height of spring shorebird migration is just a few weeks away.

This group of six sandpipers was photographed at Soap Lake, Washington on September 5, 2008. Hopefully, you can identify the birds on the far left and far right based on size (compared to the group of "peeps" in the center), the overall color, bill length and leg color. We call these birds "A" (on the far left) and "B" (on the far right). Hint: These two larger birds are the same species.

Here is a blown-up version image the four peeps seen in the middle of picture above. This close-up should give you a fighting chance of correctly identifying these four juvenile sandpipers. For the purposes of the ID challenge, we'll start with the top left bird and label the left hand group "C," "D," and "E" going top to bottom and the lone bird on the top right will be "F."

We invite you to send us your identifications of all six birds referencing them A-F (including the two larger birds in the top picture) and submit your answers by clicking on the "comments" link just under the title of this piece. We encourage you to share the field marks you used to sort out this group. Good luck, and most importantly, have fun. We'll post the answers on Monday morning.

Photo taken by David Irons using a Panasonic Lumix DMC-FZ8.