Mystery Bird: Spotted Sandpiper, Actitis macularia

tags: Spotted Sandpiper, Actitis macularia, birds, nature, Image of the Day

Read and learn from a detailed diagnosis below ..

Rick Wright, Managing Director of WINGS Birding Tours Worldwide, writes:

A thorough inspection of just about anything involves looking it over "from head to toe." Not so for birders, though, who quickly learn that the identification of many traditionally "difficult" groups is made easier by starting at the rear and working forward. This is particularly true of shorebirds, many of which are more readily identified by structural features of wing and tail than by the often transient marks of their plumage.

This particular shorebird is a sandpiper, and its rear end -- the tail and the tip of the folded wing -- identifies it immediately. A quick look at the perched bird shows that the tail extends well beyond the wingtip; among North American sandpipers, only three show so conspicuous a protrusion. Upland Sandpiper is easily eliminated by the quiz bird's short neck, horizontal posture, and relatively plain olive-brown upperparts. Distinguishing between the other two candidate species, Common and Spotted Sandpipers, requires a closer look, but our strategy of working from back to front pays off. The extension of the tail beyond the tip of the folded wing on our quiz bird is obviously less than the length of the bird's bill; that's just right for Spotted Sandpiper, while Common Sandpiper's tail protrudes a distance almost equivalent to the length of that species' bill. Moving gradually forward, we see that the edges of the feathers just ahead of the wingtip, the tertials, are unmarked, and that there are a few stray spots or streaks on the white flank; again, these characters fit Spotted but not Common Sandpiper. Moving forward even more, we see pale legs and feet, again consistent with Spotted Sandpiper and not Common. If we look at the other end of the bird, we see a pale base to the bill, another feature telling us that this is a Spotted and not a Common Sandpiper.

What would happen if we were to start at the other end, the head, as beginning birders are often tempted to do? The first thing that we'd notice is that big, bold eyering, a mark rarely mentioned in discussions of Spotted Sandpiper -- but the classic plumage character of Solitary Sandpiper. And we would find ourselves deceived. Focusing instead on the structure, particularly the structure of the rear end, we see in this quiz a long-tailed, horizontal bird that is -- even in this still photo -- obviously tipping forward, quite unlike the well-proportioned elegance and balance of a Solitary Sandpiper but exactly what we expect in a Spotted Sandpiper.

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