Birders in Canada and the United States refer to several families of long-legged wading birds in semi-

aquatic ecosystem An aquatic ecosystem is an ecosystem found in and around a body of water, in contrast to land-based terrestrial ecosystems. Aquatic ecosystems contain communities of organisms—aquatic life—that are dependent on each other and on their environ ...

s as waders. These include the families Phoenicopteridae (flamingos), Ciconiidae (storks), Threskiornithidae (ibises and spoonbills), Ardeidae (herons, egrets, and bitterns), and the extralimital families Scopidae (hamerkop) and Balaenicipitidae (shoebill) of Africa. Elsewhere in the world, the word refers to what North Americans call a " shorebird", various families of the order

Charadriiformes Charadriiformes (, from '' Charadrius'', the type genus of family Charadriidae) is a diverse order of small to medium-large birds. It includes about 390 species and has members in all parts of the world. Most charadriiform birds live near water ...

. In the past all of these families were classified in the order

Ciconiiformes Storks are large, long-legged, long-necked wading birds with long, stout bills. They belong to the family Ciconiidae, and make up the order Ciconiiformes . Ciconiiformes previously included a number of other families, such as herons and ibise ...

based on overall similarity in anatomy and ecology, as well as some molecular data. Sibley, Charles G., and Ahlquist, Jon E. 1991.
Phylogeny and Classification of Birds: A Study in Molecular Evolution
'. Yale University Press. . Accessed January 4, 2021. However recent genomic studies have found that this group to be

polyphyletic A polyphyletic group is an assemblage that includes organisms with mixed evolutionary origin but does not include their most recent common ancestor. The term is often applied to groups that share similar features known as Homoplasy, homoplasies ...

, with flamingos being more closely related to

grebe Grebes () are aquatic diving birds in the order (biology), order Podicipediformes (). Grebes are widely distributed freshwater birds, with some species also found in sea, marine habitats during Bird migration, migration and winter. Most grebes f ...

s while ibises, herons, the hamerkop and the shoebill are more closely related to

pelican Pelicans (genus ''Pelecanus'') are a genus of large water birds that make up the family Pelecanidae. They are characterized by a long beak and a large throat pouch used for catching prey and draining water from the scooped-up contents before ...

s. As a result of these changes flamingos are placed in their own order

Phoenicopteriformes Phoenicopteriformes is a group of water birds which comprises flamingos and their extinct relatives. Flamingos (Phoenicopteriformes) and the closely related grebes ( Podicipedidae) are contained in the parent clade Mirandornithes. Fossil ...

and Ciconiiformes are solely restricted to the storks. The rest of the waders have been reclassified into the order Pelecaniformes. In some field guides, the families Gruidae (cranes) and Aramidae (limpkin) are also considered to be waders too. However unlike the previously mentioned families, cranes and the limpkin were never thought to be closely related to the heron-like birds and have always been classified as members of the order Gruiformes.

References

External works

*
Life histories of North American shore birds, Part 1 (of 2)
' (1962) by A.C. Bent through Dover Publications, Inc. at New York. Bird common names Neognathae {{bird-stub