Ecological definition
Migratory birds are species where a substantial proportion of the global or a regional population makes regular cyclical movements beyond the breeding range, with predictable timing and destinations (Kirby et al. 2008).
CMS (Convention on Migratory Species) definition
Migratory birds are the entire population or any geographically separate part of the population of any species or lower taxon of wild birds, a significant proportion of whose members cyclically and predictably cross one or more national jurisdictional boundaries (Kirby et al. 2008).
Migratory Waterbirds are defined broadly as migratory birds ecologically dependent on wetlands.
For the purpose of the Partnership, migratory waterbirds include populations of shorebirds, Anatidae (ducks, geese and swans), cranes, and seabirds (for example Divers, Cormorants, Gulls, Shearwaters, and Auks) and several other groups, which cyclically and predictably cross one or more national jurisdictional boundary (see Partnership Document, Appendix 2).
Large numbers of migratory waterbirds often congregate at staging sites (typically, few such sites) for refueling during their journeys, especially before crossing large ecological barriers. Consequently, the loss of staging wetlands may have critical impacts on successful journeys and survival of migratory waterbirds.
| Taxonomic Group | English Name |
| Gaviidae | Divers/Loons |
| Podicipedidae | Grebes |
| Phalacrocoracidae | Cormorants |
| Procellariidae | Shearwaters |
| Oceanitidae | Storm Petrels |
| Pelecanidae | Pelicans |
| Ardeidae | Herons, Egrets and Bitterns |
| Ciconiidae | Storks |
| Threskiornithidae | Ibises and Spoonbills |
| Anatidae | Swans, Geese and Ducks |
| Gruidae | Cranes |
| Rallidae | Rails, Gallinules and Coots |
| Heliornithidae | Finfoots |
| Jacanidae | Jacanas |
| Haematopodidae | Oystercatchers |
| Recurvirostridae | Stilts and Avocets |
| Glareolidae | Pratincoles |
| Charadriidae | Plovers |
| Scolopacidae | Sandpipers |
| Laridae | Gulls, Terns and Skimmers |
| Stercorariidae | Skuas |
| Alcidae | Auks |
Reference: Kirby, J.S., Stattersfield, A.J., Butchart, S.H.M., Evans, M.I., Grimmett, R.F.A., Jones, V.R., O’Sullivan, J., Tucker, G.M. & Newton, I. 2008. Key conservation issues for migratory land- and waterbird species on the world’s major flyways. Bird Conservation International 18: S49-S73.