<!--ThereTidak existsada nodefinisi singletunggal definitionyang ofterdapat whichdalam groupskelompok, families[[familia]], anddan species[[spesies]] areburung seabirdslaut, anddan mostsebagian definitionsbesar aredefinisi indalam somebeberapa waycara arbitraryyang sewenang-wenang. In the<!--Dua wordsorang ofilmuwan twoburung seabirdlaut scientistsberkata, "TheKarakteristik oneyang commonumum characteristicadalah thatbahwa allsemua seabirds share is that they feed in [[seawater|saltwater]]; but, as seems to be true with any statement in biology, some do not."<ref name = "Burger">Schreiber, Elizabeth A. & Burger, Joanne.(2001.) ''Biology of Marine Birds'', Boca Raton:CRC Press, ISBN 0-8493-9882-7</ref> However, by convention all of the [[Sphenisciformes]] and [[Procellariiformes]], all of the [[Pelecaniformes]] except the [[darter]]s, and some of the [[Charadriiformes]] (the [[skua]]s, [[gull]]s, [[tern]]s, [[auk]]s and [[skimmer]]s) are classified as seabirds. The [[phalarope]]s are usually included as well, since although they are [[wader]]s ("shorebirds" in [[North America]]), two of the three species are oceanic for nine months of the year, crossing the equator to feed pelagically.
[[Loon]]s and [[grebe]]s, which nest on lakes but winter at sea, are usually categorized as water birds, not seabirds. Although there are a number of [[Merginae|sea duck]]s in the family [[Anatidae]] which are truly marine in the winter, by convention they are usually excluded from the seabird grouping. Many waders (or shorebirds) and [[heron]]s are also highly marine, living on the sea's edge (coast), but are also not treated as seabirds
