Wading birds

Wading birds, also known in North America as waders, are members of several families of long-legged birds found in semi-aquatic ecosystems. Wading birds are not a monophyletic group and different authors classify different families as wading birds. The classification always includes 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. These were once classified together in the order Ciconiiformes based on overall similarity in anatomy and ecology, as well as some molecular data. However recent genomic studies have found that this group to be polyphyletic, with flamingos being more closely related to grebes while ibises, herons, the hamerkop and the shoebill are more closely related to pelicans. As a result of these changes flamingos are placed in their own order Phoenicopteriformes and Ciconiiformes are solely restricted to the storks. The rest of the waders have been reclassified into the order Pelecaniformes.