title: The visual fields of the tawny owl, Strix aluco L.
abstract: The uniocular retinal field of Strix aluco is highly asymmetrical. The maximum width of 124 degrees is less than that recorded in any other vertebrate. Maximum retinal binocular field width equals 48 degrees and the optic axes diverge by 55 degrees. Maximum binocularity occurs above the bill whose tip lies outside of the visual field. The cyclopean retinal field has a maximum width of 201 degrees. Limited data on the visual fields of the pigeon are also presented. All of these data are compared with visual field widths in other species and the significance of the owl eye's tubular shape, its nasad asymmetry, and the possible factors influencing binocular field width are discussed.
mesh_terms: D000818:Animals; D001717:Birds / Q000033:anatomy & histology / Q000502:physiology*; D010856:Columbidae / Q000502:physiology; D005123:Eye / Q000033:anatomy & histology; D012160:Retina / Q000502:physiology; D014794:Visual Fields; D014795:Visual Pathways / Q000033:anatomy & histology