The Birds Korea Checklist, from October 2007, covers the whole of Korea (i.e. all southern and northern provinces and adjacent islands and marine areas). It also includes basic status assessments, based on unpublished data and extensive literature review (see Appendix Two for references).
The Birds Korea Checklist is divided into four categories.
Category 1 contains all species which have been recorded in 1980 or subsequently, where the identifications have been made by more than one reliable and experienced observer, in almost all cases supported by photographs, sound recordings or specimens upon which the identification can be confirmed independently.
Category 2 contains those species which were recorded reliably in the period between the start of ornithological activity in Korea (in the 1880s) and 1979, but not subsequently, with all such species supported by extant specimens or by adequate detail in the literature.
Category 3 contains all those species recorded by single experienced observers, with such observations unsupported by recognisable photographs, sound recordings or specimens; those species seen by multiple observers, but to a level considered inadequate to claim a national first record; and in a few cases, species plausibly identified through specimens which are now lost, or are in too poor condition, or are too inaccessible, to re-evaluate.
Category 4 contains species that are listed in the Korean National Parks Association Checklist (2006), where evidence seems to be lacking appropriate to their inclusion in Category 1, 2 or 3 of the Birds Korea Checklist, including those species likely originating from non-wild sources.
The Birds Korea Checklist omits at least one further species, the Red-faced Shag Leucocarbo urile, which is included in the Korean National Parks Association Checklist (2006), because literature review and research has already established that its inclusion is unwarranted.
The Birds Korea Checklist presents Korean, English and scientific names of all species reported on the Korean peninsula since the 1880s (the period of earliest known Korean ornithological survey). English names, scientific names, and the order follow Gill and Wright (2006). Most Korean names follow the checklist produced by the Korean National Parks Association (2006). (For more on the process of coining of Korean names, see Appendix One.) In some cases alternative Korean and English names are also provided, either being names that already enjoy wide usage, or (especially for taxa of special relevance to the region) have been coined by Birds Korea. In the case of English names, the first name is always that provided by Gill and Wright (2006), with the occasional use of brackets around one of the two names to denote that name’s lack of current usage by Birds Korea.
The Birds Korea Checklist is not intended as a taxonomic review. However, in a very few cases (limited to several large gulls, “Far Eastern Skylark”, and two of the Cettia warblers) some taxa of especial interest to the Korean peninsula that are not included in Gill and Wright (2006) are included in the Birds Korea Checklist as full species. Reasons for their inclusion are provided in the accompanying Notes. For a very few taxa, trinomials are also presented in the Scientific Name column. These are taxa for which simple binomial representation is considered especially misleading. For such taxa, preferred English alternative names and additional Notes are also provided.
Further, where information is adequate, subspecies recorded in Korea that are of especial potential interest to development of the Checklist (having been split off from the listed species by other specialist literature: see Notes and Appendix Two), are also listed in the Notes.
Status and Breeding
All species have two columns of status codes: one (“Status”) describing the species’ relative abundance and seasonality; the other (“Breeding”) clarifying whether the species has been documented as breeding or not. Please note that in many cases there is still inadequate evidence to assess abundance or status with a high level of confidence.
The following conventions and codes are used in Category 1, and to some degree in categories 2, 3 and 4 (see below).
The order of the codes is consistent throughout, with a very few exceptions, with each element separated by punctuation marks. In the “Status” column, the global conservation status is listed first (where required); followed by an observation on trend (where data are considered adequate to make such an assessment); followed by seasonal status, with the period of maximum abundance listed first; followed by the geographic area, only when all records have come from one geographic part of Korea alone. In a very few cases, the geographic unit (e.g. “So” or “No”) is given before the season and abundance indicator, as in the listing for Coturnix japonica. This is to indicate a very obvious difference in seasonal abundance of the same species between two separate geographical areas within Korea.
Global Conservation Status
The codes are used in accordance with Birdlife International (see: http://www.rdb.or.id):
CR: Critically Endangered.
In most cases there is insufficient data to suggest actual population trend (as opposed to perceived increase due to increased observer activity). Two codes are used to indicate only remarkable changes in selected species’ actual abundance between the period up to and including 1950 (based especially but not exclusively on Austin  and Wolfe ), compared to the present (based especially but not exclusively on Tomek [1999, 2002] and Park ).
Seasonality and Abundance
Five different letters are used in a wide range of combinations to suggest a species’ seasonality:
R(m): Resident and partial migrant.
P: Passage Migrant (i.e. spring or autumn or both).
W: Winter visitor.
S: Summer visitor or summer resident.
Five numbers (1-5) are used to express estimated abundance since 1980:
1: Numerous (ca 100,000 or more records or individuals estimated to occur annually).
2: Rather common/locally common (between 10,000 and 100,000 records or individuals estimated to occur annually).
3: Fairly common (between 1000 and 10,000 records or individuals estimated to occur annually).
4: Uncommon or rather local (between 100 and 1000 records or individuals estimated to occur annually).
5: Scarce or very local (recorded annually, with probably 100 or more records in total up between 1980 and the present, and less than 100 records estimated to occur annually).
For less regularly-recorded species, the letter “V” is used, followed by a number (1-5), to indicate all known records (from 1880 to the present):
V1: Probably annual (25-99 records or individuals recorded in total up to the present).
V2: Recorded scarcely annually, or less than annually (between ten and 25 records or individuals in total up to the present).
V3: Ten or fewer records in total up to the present.
V4: Species last recorded ten or more years before the present.
V5: Species added to the Birds Korea Checklist within the past update (starting from August 2007).
On occasion, in Category 1 only, these codes are also used with a prefix (e.g. W, S) to indicate that more abundant species also occur more rarely in a given season. At such times, all such records refer to the period between 1980 and the present.
In this way, the code combination “S3, WV3” indicates that a species which is fairly common in summer has also been recorded less than 10 known times in the mid-winter period between 1980 and the present.
Provided in columns on “Abundance and seasonality” and “Breeding” only for those species which have been recorded in one of the units of area alone.
No: north of approximately 38 D North.
So: south of approximately 38 D North.
N-N: Far northern provinces: Pyonganbuk, Chagang, Yanggang, Hamgyeongnam, Hamgyeongbuk.
N-C: Northern-central provinces: Pyongannam, Hwanghaebuk, Hwanghaenam, northern Gangwon.
C-W: Central-western provinces: Gyeonggi, Chungchongnam, Chungchongbuk.
C-E: Central-eastern provinces: southern Gangwon, Gyeongsangbuk.
S-S: southern provinces: Jeollabuk, Jeollanam, Gyeongsangnam, excluding Jeju and the southern coastal zone.
S-C: Southern Coastal Zone, all islands and within ca 20km of the coast in Jeollabuk, Jeollanam, Jeju, Gyeongsangnam and Gyeonsangbuk provinces.
Six codes are used:
C: Breeding Confirmed. Breeding confirmed by unambiguous evidence (photographs, specimens or detailed notes) of one or more of the following: nest, eggs, flightless or poor-flying juveniles food-begging from adults.
P: Presumed Breeding. Breeding can be presumed, in the absence of unambiguous evidence as above, when a sedentary or near sedentary species is recorded across years in suitable breeding habitat during the breeding season; or when a pair or more of a species shows obvious breeding-related behaviour in appropriate habitat and season. Most presumed breeders have been identified as such in the relevant literature.
S: Suspected breeding. Breeding is suspected in the absence of unambiguous evidence, when a pair or more of a species is either in potentially suitable breeding habitat during the breeding season, or when young full-winged juveniles of a species have been observed in mid-summer, outside the period of usual occurrence.
(S): Species Suspected to breed by earlier authors, but for which the evidence seems less than compelling.
(br): According to the available Korea-specific literature, either confirmed or presumed to have bred historically (pre-1950) but not subsequently.
Blank: Believed not to breed in Korea, either historically or at present, in a very few cases contrary to earlier Korea-specific literature.
The first five (a-e) of the following six symbols can in turn be followed by codes for “Geographic Area” as outlined above.
In Category 2, the “Status” column provides information different from that given for species in Category 1. In Category 2, each species contains an assessment of global conservation status (as above); followed by:
The number of published records of that species;
The year of the last confirmed record.
Use of geographic codes in both the “Status” and the “Breeding” columns are as in Category 1 above.
In Category 3, the “Notes” column contains four additional codes, SR, SP, PH, PUB:
SR: Sight Record.
SP: Specimen Record, when there are reasonable doubts as the identification of the specimen, due to its age or inaccessibility.
PH: Photograph Record, when the photograph fails to reveal diagnostic identification features, or to indicate that the photograph was taken inside of Korea.
PUB: Published, when the basis of the record seems unclear or disputed.
(Please go to the Appendix One for Additional Information on the development of the Birds Korea Checklist, and Appendix Two for References in the Birds Korea Checklist Introduction PDF-document.)