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Variable SanderlingsBird-identification help: Sanderlings
Contributed by Kenn Kaufman
Published: June 24, 2011  Click to enlarge
Sanderlings are the most familiar of shorebirds, found for most of the year on any sand beach. Their wave-chasing and pale plumage make them instantly recognizable, but familiarity can work against us: Where there are no waves, Sanderlings don’t chase them; the birds often walk slowly, picking at the surface. And they aren’t always pale and plain.
Almost all members of the sandpiper family have distinct adult breeding, adult winter, and juvenile plumages. In some species, the differences are subtle, but in Sanderlings they are obvious. Late summer is an excellent time to look at the species. Adults may leave their high Arctic breeding grounds by early July — or even by late June, if their first nesting attempt fails. By late July, beaches in the United States and southern Canada may have many adults in fading remnants of breeding plumage. In mid-August, the first juveniles show up, crisp and contrasting, different from their elders. Study of Sanderlings in late summer is good preparation for seeing plumage differences in other shorebirds.
Variation in spring Sanderlings is also remarkable, in a different way. Spring adults run the gamut from very pale birds, superficially much like winter plumage, to others that are mostly brick-red. Males tend to show more reddish than females, and adults of each sex tend to show more reddish than one-year-old birds, but timing of the molt also varies individually, so it would be challenging to guess the age and sex of any given individual.
So what’s the best way to identify the bird throughout the year? The best field mark is shape. Sanderlings are heavy-bodied, large-headed, short-necked birds, and their bills are short, straight, stout, and blunt at the tip. As you gain experience, you should be able to recognize them regardless of plumage colors.
Even so, birders sometimes misidentify the red-headed late-spring adults as a rare Alaskan/Siberian specialty, the Red-necked Stint. The stint is smaller and thinner-billed, and there are some plumage differences, but for a definitive way to separate the Sanderling from all the small “peeps” and stints, look at the feet. The Sanderling is the only member of this group that lacks a hind toe, and this difference can be seen at close range. |
What to look for
Overall shape.
Stocky, big-headed, short-necked, always with a compact look.
Bill shape. Short and straight, thick throughout its length and blunt at the tip.
Plumage color. Varies by season. Plain and pale in winter, but some in breeding plumage are deep rufous. Juveniles are spangled black and white above.
Dark shoulder mark. Black feathers on leading edge of wing create dark “shoulder,” but this is often hidden even on winter birds and shows little contrast in breeding and juvenile plumages.
Face pattern. Relatively plain, with little obvious contrast, except on juveniles.
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Double life
The Sanderling’s change in plumage may seem extreme, but its changes in location are even more so. While many shorebirds go to northern tundra to nest, the Sanderling goes far beyond most, to sites far above the Arctic Circle. Point Barrow, Alaska, the northernmost point in the United States, is too far south for them; most go to high Arctic islands of Canada, the northern coast of Greenland, the islands of Spitzbergen (north of Norway), or the highest latitudes of Russia. I’ve never seen a Sanderling on the breeding grounds, nor have most of my friends; it’s a major project to get that far north.
When Sanderlings leave their remote breeding grounds, however, they disperse over most of the planet, or at least to most of the planet’s coastal zones. Perhaps no other birds can be found in winter over a range of latitude so wide. Some Sanderlings can be found all winter on rocky shorelines in the Maritime Provinces of Canada and on the Aleutian Islands of Alaska. They extend south from there, almost continuously along the coastlines, close to the southern tip of South America in Tierra del Fuego! Others can be found wintering around southern Africa, Australia, and New Zealand.
So our familiar little beach bird is actually an extraordinary traveler. It serves not only as an exercise in bird identification but also as a reminder that even familiar birds do amazing things and deserve our respect.
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Kenn Kaufman is the author of the Kaufman Guide to Birds of North
America, Kaufman Field Guide to Advanced Birding, and other books about
birds.
Read more by Kenn Kaufman.
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