The following categories exist on the wiki, and may or may not be unused. Also see wanted categories.
(first | last) View (previous 50 | next 50) (20 | 50 | 100 | 250 | 500)- Oreostruthus (1 member)
- Oreothlypis (8 members)
- Oreothraupis (1 member)
- Oreotrochilus (7 members)
- Oressochen (0 members)
- Origma (1 member)
- Oriolia (1 member)
- Oriolidae (4 members)
- Oriolus (29 members)
- Oriturus (1 member)
- Orkney Islands (8 members)
- Ornithion (3 members)
- Ornorectes (1 member)
- Oroaetus (1 member)
- Orochelidon (3 members)
- Ortalis (15 members)
- Orthogonys (1 member)
- Orthonychidae (1 member)
- Orthonyx (3 members)
- Orthopsittaca (1 member)
- Orthorhyncus (1 member)
- Orthotomus (13 members)
- Ortygospiza (3 members)
- Ortyxelos (1 member)
- Oryzoborus (0 members)
- Other Wildlife (1 member)
- Other Wildlife Videos Or Dvd's (1 member)
- Otididae (12 members)
- Otidiformes (1 member)
- Otidiphaps (1 member)
- Otis (1 member)
- Otus (51 members)
- Outer Hebrides (4 members)
- Oxfordshire (2 members)
- Oxylabes (1 member)
- Oxylophus (0 members)
- Oxypogon (4 members)
- Oxyruncidae (4 members)
- Oxyruncus (1 member)
- Oxyura (6 members)
- Pachycare (1 member)
- Pachycephala (47 members)
- Pachycephalidae (7 members)
- Pachycephalopsis (2 members)
- Pachycoccyx (1 member)
- Pachyphantes (0 members)
- Pachyptila (6 members)
- Pachyramphus (16 members)
- Pachysylvia (0 members)
- Pacific Islands (21 members)


