Category A-C (passerines)
All records have been verified using the criteria laid out by A. H. J. Harrop (2011) in British Birds, vol. 104. p. 163. After the first for Britain of any given species has been accepted by the BOURC, it is the prerogative of each county records committee to adjudicate on all records prior to 1950 for their own county, so I have added the latest county avifauna or Bird Report reference as their acceptance. In certain cases some of these records have been rejected assuming that the county records committee do not have the information that I have about the record.
Regarding the rarities the original reference history is used to validate the records of any species.
Records for species are in order of date, but those undated are placed at the rear for that year in alphabetical order of county, locality.
The four seasons are classed: Winter (Dec. - Feb.), Spring (Mar. - May), Summer (Jun. - Aug.) and Autumn (Sep. - Nov.).
Taxonomic order follows AviList Core Team. 2025. AviList: The Global Avian Checklist, v2025, displaying the Family followed by indented species. Species with trinomials are accepted BOURC sub-species.
Each species has in parenthesis after the scientific name of the species two numbers, the first figure denoting the number of records up to 31st December 1949, with the second figure for those recorded between 1950-57.
There are generally three headers under each species: RECORDS, 1950-57 RECORDS and NOT PROVEN.
