are birds that spend much of their lives, outside the breeding season at least, at sea. Some species, such as the albatrosses and petrels are truly pelagic, breeding on sea cliffs and small islands, and wintering on the open ocean. They are totally dependent on the sea for food. Many of these deep water species can barely walk on land.
Other species such as the auks are equally dependent on cliff-ledge breeding sites and marine prey, but tend to be more coastal once they have migrated from their breeding stacks.
Some of the less oceanic species, like grebes and divers, breed in freshwater environments but move to the coasts in winter. A few, such as the Great Crested Grebe and the Anhinga, will also winter on freshwater lakes where they remain unfrozen.
The following are the groups of birds normally classed as seabirds.
Sphenisciformes (Antarctic and southern waters; 16 species)
(North America, Eurasia; 4 species)
(Worldwide; 20 species)
(Tubenoses: pan-oceanic and pelagic; 93 species)
- Diomedeidae albatross
- Procellariidae fulmars, prionss, shearwaters, gadfly and other petrels
- Pelacanoididae diving petrels
- Hydrobatidae storm-petrels
(see also petrel
Pelecaniformes (Worldwide; 57 species)
(Worldwide; 305 species, but only the families listed are classed as seabirds.)
- Stercorariidae skuas
- Laridae gulls
- Sternidae terns
- Rhynchopidae skimmers
- Alcidae auks
- Chionididae Sheathbills
For an alternative taxonomy of these groups, see also Sibley-Ahlquist taxonomy
Sometimes the phalaropes are included in the seabirds, since although they are waders ("shorebirds" in North America), two of the three species are oceanic outside the breeding season.
Although there are a number of sea ducks in the family Anatidae which are truly marine, by convention they are usually excluded from the seabird grouping.
See also list of birds.