Birds are divided into eight main visual categories: (1) swimmers—ducks and ducklike birds, (2) aerialists—gulls and gull-like birds, (3) long-legged waders—herons and cranes, (4) smaller waders—plover and sandpipers, (5) fowllike birds—grouse and quail, (6) birds of prey—hawks, eagles, and owls, (7) passerine (perching) birds, and (8) nonpasserine land birds.—A Field Guide to the Birds East of the Rockies, by Roger Tory Peterson.
Ang mga ibon ay maaaring uriin sa walong pangunahing nakikitang kategorya: (1) lumalangoy —mga pato at tulad-patong ibon, (2) lumilipad —mga golondrina at tulad-golondrinang ibon, (3) nagtatampisaw na may mahahabang binti —mga kandanggaok at tipol, (4) mas maliliit na nagtatampisaw —talingting at mga sandpiper, (5) tulad-manok na mga ibon —mga ave silvestre at pugo, (6) ibong maninila —mga lawin, agila, at kuwago, (7) mga passerine (dumadapo) na ibon, at (8) mga nonpasserine na ibong panlupa. —A Field Guide to the Birds East of the Rockies, ni Roger Tory Peterson.jw2019 jw2019