Oceanic birds found in Micronesia belong to the following families: Diomedeidae, Procellariidae, Phaëthontidae, Pelecanidae, Fregatidae, and Laridae. Following Wynne-Edwards (1935:240) and Murphy (1936:326), these birds may be grouped as inshore birds (Laridae and others), offshore birds (Pelecanidae, Fregatidae and others), and pelagic birds (Diomedeidae, Procellariidae, Phaëthontidae). As shown in table 2 there are 30 kinds of oceanic birds in Micronesia, 18 kinds that are resident and 12 kinds that are regarded as visitors to the area. Records of nestings are few; field work in the future probably will yield evidence that more kinds of oceanic birds are actually resident in the Micronesian islands. TABLE 2. LIST OF RESIDENT AND NONRESIDENT OCEANIC BIRDS OF MICRONESIA -------------------+----------+------------- Genera | Resident | Nonresident | kinds | kinds -------------------+----------+------------- _Diomedea_ | 0 | 1 _Puffinus_ | 4 | 1 _Pterodroma_ | 1 | 1 _Phaëthon_ | 2 | 1 _Sula_ | 3 | 0 _Fregata_ | 1 | 1 _Larus_ | 0 | 1 _Chlidonias_ | 0 | 1 _Sterna_ | 2 | 4 _Thalasseus_ | 1 | 0 _Procelsterna_ | 0 | 1 _Anoüs_ | 2 | 0 _Gygis_ | 2 | 0 -------------------+----------+------------- INSHORE OCEANIC BIRDS The inshore zone, according to Wynne-Edwards (1935:240), "extends from high-water mark to a maximum of four or five miles out to sea, including islands and reefs within sight of shore." In Micronesia the majority of the Laridae occur in this zone including such residents as _Sterna sumatrana_, _S. anaetheta_, _Thalasseus bergii_, _Anoüs stolidus_, _A. tenuirostris_, _Gygis alba_. These birds, especially _S. anaetheta_, _Thalasseus_, and _Anoüs_, may venture into the offshore zone. Visitors to Micronesia include several terns which probably normally range in the inshore (as well as in offshore) zones, such as _Childonias leucopterus_ and _Sterna hirundo_. These birds feed to a considerable extent inside the outer reefs surrounding the lagoons, coming to shore frequently in small or large groups. _Gygis alba_ probably spends considerable time on shore; stomachs examined contained fish, crustaceans and insects, indicating that they obtain some of their food ashore. OFFSHORE AND PELAGIC OCEANIC BIRDS