Birds of Seabrook Island






Species Acct.
NW Warblers


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  Order Charadriiformes - Plovers, Sandpipers, Gulls, Terns, Auks
   Family Scolopacidae - "Sandpipers"
      Tribe Calidridinae - Calidrines

  Charadriiforms are a diverse group of shore and aquatic or wading or terrestrial birds. They include the sandgrouse, shore birds, gulls and terns, and alcids. The majority breed in the Northern Hemisphere.
   The Tree of Life includes shorebirds with the Ciconiiformes.
Sandpipers are a diverse group of shorebirds with bills not swollen at the tip. Most live in association with water. Short-billed forms feed on the surface using vision. Long-billed forms probe in mud and their prey is located by touch or smell. Tides influence their feeding cycles.   
Calidrine Sandpipers include species in Aphriza, Calidris, Euynorhynchus, Limicola, Philomachus, and Tryngites. The smaller calidrines are often referred to as "peeps" or stints. Most species are small and identifications can be difficult. They feed along the shore and mudflats or in shallow water. Most undergo long migrations, breeding in the Arctic and wintering south to South America.
Key Species of Shorebirds
Salt Glands
  Sanderling, Calidris alba
Cornell     USGS     Wiki     ToL     EoL
        YEAR ROUND - Common / Common
            SANDY BEACH, MUDFLATS (coastal)
   Sanderlings are the ubiquitous shorebirds found dashing in and out of the surf while avoiding waves. They seem to be in constant motion as they feed in the surf - like "clockwork toys." They also feed more deliberately above the swash zone and on mud flats but they really characterize "shorebirds" on the beach.
   Sanderlings have a relatively short dark bill and dark legs. The leading edge of their wing is black and the wing has a broad white wing-stripe. The central rail feathers are dark and the lateral feathers white. In winter Sanderlings are a pale gray on the back and white underneath. As the breeding season approaches, their neck, face, and some of the feathers on the back become rufous - the bird now appears dark in contrast to its very light winter plumage.
   While Sanderlings normally evade incoming waves, I have seen them bathe in the waves, performing a complete cleaning of their bodies and wings.
   Although Sanderlings are calidrine sandpipers, most birders probably don't include them with the "peeps" or, if they do, consider them a large peep.


Sanderling. North Beach

  Key Species of Shorebirds
   While identifying shorebirds, there are two "key" species that need to be learned well in all plumages. They provide reference points against which all other shorebirds can be compared. These are the Willet and the Sanderling.
   Willets are 15" long, nondescript gray shorebirds of medium size (they give away their identification with they fly - showing a white wing-stripe and grayish tail). They are found on our high-energy beaches as well as estuaries and mud flats.
   Sanderlings are smaller, about 8" in length, and may be considered the largest of the "peeps," a confusing group of small sandpipers. In winter, sanderlings are a pale gray with white under-parts and straight black bills and black feet. In breeding plumage they develop rufous feathers on the head, neck and back but we see them in this plumage for only a brief period. Sanderlings have a white stripe in the wing and dark central tail feathers. These are the ubiquitous "surf birds" running in and out of the swash year round.
   Concentrate on learning these two species and use them to compare with others.
  RANGE: Sanderlings breed in the high Arctic on tundra of the islands of the Arctic Ocean and the northern edge of Hudson Bay. They winter along both coasts, south through The West Indies and South American south to Tierra del Fuego. However, many stragglers appear on our beaches year round - in the summer they are non-breeding birds or early migrants returning after unsuccessful breeding. In winter they are birds who managed to survive without making the longer trip.
   Sanderlings also breed on the east coast of Greenland and in the high Arctic islands and tundra of the Old World. They spend the winter along the shores from northern Europe and the British Isles south around Africa, the Arabian Peninsula, India, islands in the Indian Ocean, southeast Asia and Oceana to Australia and New Zealand. They have virtually a worldwide distribution.
  BREEDING: Dry sedge, barren or stony tundra areas, but near water. Monogamous (limited polyandry). One (sometimes 2) broods. The nest is a scrape lined with grass, leaves, or lichens. The nest scrape is usually in the open and may be somewhat barren and elevated. The female selects one of several and lays 4 (3-4) eggs. Both sexes incubate for 24-31 days. (Sometimes the female lays a second clutch which the male incubates while she tends the first. She may also have two mates. leaving each male to raise the young while she takes off.) Young are precocial. Downy young leave the nest after hatching and are tended by one or both parents. If both parents are present, the female may leave soon after the young hatch. They fly after 17 days.
  DIET: Sanderlings feed on sand crabs and other invertebrates plus insects, spiders, vegetation and some carrion. They probe for marine invertebrates within 1 cm of the surface. The bill is partly open as they work the sand. They chase the waves to find sand crabs which are easy to spot as a wave recedes. They more rapidly as the feed.
  VOICE: Sanderlings utter a short had "klit" and feeding flocks may give scratchy "tiv" calls. They generally forage quietly.
   Checklists -
      Seabrook. Kiawah - common year round. Edisto - resident.
      Coastal - common winter visitor. Hilton Head - common winter visitor. Cape Romain - abundant/common/abundant/abundant.
         Huntington Beach
- common April - May; uncommon June; common July - February; uncommon March.
   CBC: Charleston 50, 408, 211, 106, 314, 201, 52, 37;
         St, Helena/Fripp x, x, x, x, x, x, 311, 322; Hilton Head 181, 880, 483, 541, 823, 219, 588, 575; Sun City/Okatie 130, 48, 0. 0, 0, 61, 35, 46;
         McClellanville 44, 103, 75, 148, nc, 144, 79, 133; Winyah Bay x, x, 79, 41, 22, 124, 167, 75;
            Litchfield/Pawley's 125, 147, 288, 73, 282, 293, 240, 115.
   P&G: Resident, common in winter, uncommon in summer, very common during migration. Maximum 452, Hilton Head, 29 December 1984.
   Avendex: 1 record, maximum (above).
   Potter: Common to abundant resident with fewer present in the summer.
  ●  Look for Sanderlings on the beach. They are common on Seabrook. They may forage individually or in small groups, usually in the swash zone with excursions to the higher beach. Like other shorebirds, they feed with the tides, not the day/night cycles so you may find them feeding at night.
   Sanderlings, turnstones, and some other shorebirds will probe horse droppings on the beach for goodies...

Salt Glands

   Many birds living on the beach have supraorbital glands that lie in bony depressions on each side of the skull over the bony eye socket on each side and under the skin (they are subcutaneous) with ducts that empty into the nasal cavity. These glands are capable of removing excess salt from the blood - up to 5X the concentration in body fluids) and excreting it to the environment. (Mammals are the only vertebrate capable of producing hypertonic urine in the kidney.)
   The production of this hypertonic excretion involves countercurrent flow and active sodium transport but mechanisms have not been established. The gland lacks the structure found in the kidney and needs further study.
   Salt glands are large in many birds living in marine environments. In birds like the Ring-billed Gull that breeds in fresh-water areas, they are reduced during the summer and become enlarged when the birds winter on the coast. They are found in many different birds including some perching birds. They are also functional in marine reptiles (marine iguanas, Galapagos Islands).
   A Sanderling in one of the pictures in the gallery is loosing a drop of excreted salt water. Watch gulls perched on pilings - you will often see these excretions dripping from their bills.
    Banner - Sanderlings, North Beach.

KEY:    ■ Seabrook list     □ Kiawah list