Dunlin Calidris alpina
A calidrid wader
Scientific classification
Class: Aves
Order: Charadriiformes

Waders, called Shorebirds in North America (where "wader" is used to refer to long-legged wading birds such as storks and herons), are members of the Charadriiformes order of birds, but excluding the more marine web-footed seabird groups. The latter are the skuas (Stercoraracidae), gulls (Laridae), terns (Sternidae), skimmers (Rhynchopidae), sheathbill Chionididae and auks (Alcidae).

This leaves about 210 species, most of which are associated with wetland or coastal environments. Many species of Arctic and temperate regions are strongly migratory, but tropical birds are often resident, or move only in response to rainfall patterns. Some of the Arctic species, such Little Stint are amongst the longest distance migrants, wintering in the southern hemisphere

The majority of species eat small invertebrates picked out of the mud or soil. Different lengths of bills enable different species to feed in the same habitat, particularly on the coast, without direct competition for food.

Some larger species, particularly those adapted to drier habitats will take larger prey including insects and small reptiles. The pratincoles are aerial insect eaters, hunting like swallows.

Many of the smaller species found in coastal habitats, particularly but not exclusively the calidrids, are often named as "Sandpipers", but this term does not have a strict meaning, since the Upland Sandpiper is a grassland species.

The following shows the groups of Charadriiform birds normally classed as waders. The approximate number of species is in brackets.

The large family Scolopacidae is often further subdivided into groups of similar birds. These groups do not necessarily consist of a single genus. The groups are

  • Godwits (4, all genus Limosa)
  • Curlews (8, all genus Numenius)
  • Upland Sandpiper (1 genus Bartramia)
  • Shanks and Tattlers (16)
  • Polynesian sandpipers (2)
  • Turnstones (2, both genus Arenaria)
  • Phalaropes (3, all genus Phalaropus)
  • Woodcocks (6, all genus Scolopax)
  • Snipe (16)
  • Dowitchers (3, all genus Limnodromus)
  • Calidrids and allies (25, of which 20 in genus Calidris )

In the Sibley-Ahlquist taxonomy, waders and many other groups are subsumed into a greatly enlarged order Ciconiiformes.

See also list of birds