The official list of birds recorded on the Isle of Man is maintained by the Manx Ornithological Society (MOS). Species are allocated into a category by the MOS according to their likely origin and current status. The categories are similar to those used for the British List maintained by the British Ornithologists’ Union’s Records Committee (BOURC).
Category A: Species that have been recorded on the Isle of Man in an apparently natural state at least once since 1st January 1950.
Category B: Species that would otherwise be in Category A but have not been recorded since 31st December 1949.
Category C: In the Manx List this is sub-divided:
- C applies to species that have establish breeding populations derived from introduced stock, that maintain themselves on the Isle of Man without necessary recourse to further introduction.
- C* applies to species fulfilling the above requirements in Britain, but do not breed on the Isle of Man and have occured there naturally as visitors.
Category D: Species that would otherwise appear in Category A or B except that there is reasonable doubt that they have ever occurred in a natural state.
Category E: Species that have been recorded as introductions, transportees or escapees from captivity, and whose breeding populations (if any) are thought not to be self-sustaining.
For the current lists please follow the links below: