by
Jim Hailey
Small sandpipers, often referred to as peeps, pose identification difficulties for most new birders. These birds are found in our area during migration and often spend winter months with us. They can be found around small ponds and lakes such as Granger and at other location like Hornsby Bend. Key characteristics which you can use to separate the three (Western, Semipalmated, and Least) focus on leg color, bill length and bill shape, as well as other less evident field marks. So let’s explore these three species and point out some important field marks to look for in your quest to separate them.
All three range from 6 to 7 inches in overall length and are generally gray to gray-brown making size or coloration hard to provide clues. This is especially true when they return from their breeding grounds in basic plumage during the fall migration. In Spring migration, color can provide valuable clues to determine the identification to a greater degree. So, for the most part, neither of these attributes is of much help.
First let’s examine the Western Sandpiper. The two most important field marks to check are the bill length, shape and color. Note that this species has a rather long (relative to head size) bill that is slightly down turned near the tip. Its legs are black as well, although you must be careful here as sometimes the bird legs are covered with mud that obscure their true color. The yellow line indicating the brown ear coverts is characteristic in spring migration but not present in their fall return, nor the dark brown cap. Underparts are gray-to-white in basic plumage, but they display dark-chevroned marks on their underparts in spring breeding plumage. So to summarize the best field marks to focus on are the bill and legs.
Next let’s examine the other black legged, black billed peep, the Semipalmated Sandpiper. While this species does have black legs like the Western, the bill size and shape is different. Semiplamated Sandpiper’s bills are blunt at the end and are usually shorter in relation to head size that their Western counterpart. In addition, in both basic and breeding plumage, their underparts are white and they have a pale to slightly streaked breast band in contrast to the heavier one of the Western. So here we center our efforts on the bill length and shape.
Now we move on to the third of these peeps, Least Sandpiper. Here we note the very different leg color. Their legs are yellow. Again, we must be careful here because these birds feed along the muddy edges of ponds, often obscuring the true color. Now to the bill. Like the other two they have black bills but note that their bills are much shorter slightly de-curved overall. However, the leg color is diagnostic and the quickest way to separate this species from the other two. So now you have the tools to make the somewhat challenging identifications make a trip out and put this information to use.
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