Welcome to Birds of the World!
You are currently viewing one of the free accounts available in our complimentary tour of Birds of the World. In this courtesy review, you can access all the life history articles and the multimedia galleries associated with this account.
For complete access to all accounts, a subscription is required.
Already a subscriber? Sign in
Most sandpipers are clothed in muted earthtones that match the simple and elemental habitats where they live, and their bills have evolved to capture invertebrates in mud and sand in almost every conceivable way. Females in some species may achieve higher fecundity by mating with more than one male, and polyandry, polygyny, and monogamy can occur in congeners that look outwardly very plain and very much the same. These different mating systems are associated with some very fluid patterns of movements as well; some species seem to wander from place to place to breed both within and between seasons. In addition some birds in this family make the longest-distance nonstop migrations of any terrestrial bird.
- Most species brown or gray above and white below, with many having rufous on underparts and as highlights above; back usually streaked and lined cryptically
- Body small to medium, streamlined ovoid in shape
- Bill thin, short, and straight to very long and decurved or slightly recurved
- Head typically small, rounded; neck short to medium-long
- Legs and toes usually long, delicate, partially webbed in some
- Sexual dimorphism highly variable; male or female may be larger or more brightly colored depending on each species’ reproductive strategy; many species sexually monomorphic
Scolopacids generally prefer to breed in wet, open, grassy habitats, and a large number of species nest on Arctic or subarctic tundra. Other species may breed along beaches or rocky coasts, in forested habitats, or on dry grasslands. During the non-breeding season, most members of this family are found in intertidal habitats, especially mudflats at the mouths of estuaries and in large bays where food is particularly abundant. Other species prefer nontidal wet grasslands. Phalaropes (Phalaropus), are unusual in spending the non-breeding season in the tropics on the open ocean.
Scolopacids take advantage of the superabundance of insects on their breeding grounds, where the diets consist largely of insect larvae and seed. At other times, their diets consist mostly of other invertebrates, from tiny copepods and cockles to a huge diversity of worms to mid-sized crabs. Some species eat grain on the non-breeding grounds, and many species will eat roots, seeds, and shoots when invertebrates are scarce. But no other species comes close to the plant reliance exhibited by the Tuamotu Sandpiper Prosobonia parvirostris, which forages to a great extent on nectar from shrubs and trees on the remote central Pacific atolls where it lives (Burle et al. 2013). The bills of many scolopacids are adapted to particular feeding strategies, with curlews (Numenius) and godwits (Limosa) able to forage deep in mud for their preferred prey, and turnstones (Arenaria), which have probably the broadest diet of any scolopacid, able to flip small rocks or dig into a carcass or crab with their wedge-shaped bills. The phalaropes uniquely sit on the water and spin in circles, churning small plankton up to the surface where they are more easily caught.
Scolopacids exhibit most of the different mating systems known for birds. Sandpipers in the genus Calidris vary from polygynous lek breeders to monogamous to polyandrous breeders. Phalaropes are polyandrous and have marked reverse sexual dichromatism. Some species exhibit multiple mating systems within a single population of the same species, but it appears likely that most species are monogamous most of the time. Most scolopacids nest on the ground, constructing a small cup or depression that may be lined with grass, leaves, or other material, though some in the genus Tringa appropriate the abandoned nests of other birds in trees. Most scolopacids lay a clutch of 4 eggs, although they may lay 2 or 3 eggs, especially if laying a replacement clutch. After about three weeks of incubation, the precocial chicks hatch. They generally leave the nest soon thereafter, thermoregulating themselves except in extreme environments, where adults may brood the chicks for many weeks during very cold periods. The chicks generally feed themselves, except in Gallinago and Scolopax, in which the adults feed the chicks at first.
Scolopacidae includes some of the rarest birds in the world; several species are already extinct, and 27 others (30%) are at risk (14 NT, 7 VU, 3 EN, 2 CR, 1 CR (PE)). One of the most famous sandpipers is the Eskimo Curlew Numenius borealis, which was hunted to near extinction in the 19 century in North America, and may now be extinct. The Slender-billed Curlew N. tenuirostris has suffered a similar fate, and may likewise be extinct. While hunting pressure forced these two curlews to near extinction, two other well-documented extinctions, of Prosobonia species on small Pacific islands, were caused by the introduction of non-native species and habitat destruction. Habitat destruction is the current danger for many other rare and declining shorebirds, including the Spoon-billed Sandpiper Calidris pygmaea. Loss of migratory habitat and subsistence hunting on the wintering grounds have all but doomed this peculiar shorebird to extinction, although recent captive breeding measures provide a glimmer of hope.
Scolopacidae is part of the suborder Scolopaci of Charadriiformes and appears to be sister to all the other families in this suborder: Jacanidae, Rostratulidae, Thinocoridae, and Pedionomidae (Thomas et al. 2004, Paton & Baker 2006, Baker et al. 2007a, Fain & Houde 2007, Gibson 2010, Pereira & Baker 2010, Gibson & Baker 2012). Within Scolopacidae, Scolopacinae is likely sister to Tringinae, and together these appear to be sister to Calidrinae. Limosinae appears to be sister to these three, with Numeniinae sister to all four subfamilies (Baker et al. 2007a, Gibson & Baker 2012).