List Determination & Taxonomy

Masked Booby Sula dactylatra Hawaii, USA.  Photo by George Wallace.

The original list of seabirds used throughout this site was produced by extracting all members of the Alcidae, Anatidae, Chionidae, Diomedeidae, Fregatidae, Gaviidae, Hydrobatidae, Laridae, Pelecanidae, Pelecanoididae, Phaetontidae, Phalacrocoracidae, Podicipedidae, Procellariidae, Spheniscidae, Stercorariidae, Sulidae and the two members of the genus Phalaropus (Scolopacidae) from the taxonomy accepted by the International Ornithologists’ Committee (IOC) (version 3.4), which yielded 555 species. The seabirds were extracted from this list by using BirdLife International’s categorization of species as seabirds which yielded 351 species. Subspecies not recognized at the species level by the IOC were eliminated. All species new to science, as well as sister and daughter taxa of species present in the BirdLife stratification of the IOC list were included (e.g. the former members of Puffinus lherminieri). This yielded a total of 371 species. Six extinct species were eliminated from the list. A few species were added as research progressed and it became clear that these additional species merited inclusion as they use the marine environment for a significant portion of their lifecycle or seasonal movements and/or have been documented in marine fishing gear.

In the current update (2021), we reviewed taxonomic changes between the original list and the IOC list (version 11.1). Between the two versions, there were eight new species added (split from species in the 2015 list), and two species lost (lumped into previously-existing species). Some scientific and common names had also been changed; these were updated to the current version. The current taxonomy now has a total of 384 species of seabirds for which full profiles have been developed. The full list is in the table below.  

Basic information on population status, foraging ecology, phenology and ship-following behavior was collected for each species. Population status relies to a large extent on IUCN evaluations; if the figures are derived from other sources this is noted in the Ecology Notes. Some species accepted by the IOC [particularly the southern ocean (Imperial) Shag complex (Phalacrocorax atriceps) split into several species and here treated as the Leucocarbo spp.] are not recognized by BirdLife International, and are thus not evaluated by the IUCN as to Red List status. Please see the Definitions page for precise descriptions of each of the fields used in a species profile.