Mystery Bird: Spotted Sandpiper, Actitis macularia

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[Mystery bird] Spotted Sandpiper, Actitis macularia, photographed at Smith Point, Texas. [I will identify this bird for you tomorrow] [voice mp3: Gough, G.A., Sauer, J.R., Iliff, M. Patuxent Bird Identification Infocenter. 1998. Version 97.1. Patuxent Wildlife Research Center, Laurel, MD].
Image: Joseph Kennedy, 7 September 2008 [larger view].
Nikon D200, Kowa 883 telescope TSN-PZ camera eyepiece 1/1600s f/8.0 at 1000.0mm iso400.

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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About GrrlScientist

grrlscientist is the pseudonym of an evolutionary biologist and ornithologist who writes about evolution, ethology, and ecology, especially in birds. After earning a degree in microbiology (thesis focus: virology) and working at the Fred Hutchinson Cancer Research Center in Seattle, she earned her PhD in zoology from the University of Washington in Seattle, where she studied the molecular correlates of testosterone and behaviour in white-crowned sparrows. She then worked a Chapman Postdoctoral Fellow at the American Museum of Natural History in New York City, where she studied the speciation and distribution of lories and other parrots throughout the South Pacific Islands. A discarded scientist, she returned to her roots: writing. Formerly hosted by The Guardian (UK), she now writes about science for Forbes and for the non-profit think tank, the Evolution Institute and she writes podcasts for BirdNote Radio. An avid lifelong birder and aviculturist, she lives with a flock of songbirds and parrots somewhere in Germany.
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0 Responses to Mystery Bird: Spotted Sandpiper, Actitis macularia

  1. JPS says:

    Spotted sandpiper

  2. RM says:

    solitary sandpiper

  3. Rick Wright says:

    With many groups of birds, it’s most useful to start at the rear and work forwards. This is particularly true of shorebirds, and this species in particular has a distinctive character there, one that will allow you to distinguish it from an Old World congener that might, just might, someday occur in Texas.
    As always, I’m eager to read how people work through this identification.

  4. The Ridger says:

    Oh! I know that one! It’s Joey!
    Sandpiper. That’s as far as I can go with certainty.

  5. Smilodon says:

    Spotted Sandpiper.

  6. L French says:

    Date: Wednesday, September 17, 2008, 3:35 PM
    Spotted Sandpiper (Actitis macularia) (non-breeding plumage). I have had the rare pleasure of growing up on National Wildlife Refuges around the U.S. and see these guys in all phases their of plumage.

  7. JohnB says:

    Juvenile Spotted Sandpiper

  8. Cody says:

    I’m thinking Spotted Sandpiper on this one, even though my first instinct WAS Solitary.