Great Black-backed Gull
WR r (Miss. R.), ca (elsewhere)
PR--permanent resident; some individuals present year round.
SR--summer resident; a breeder, between 1 June and 31 July.
SV--summer visitor; a non-breeder.
WR--winter resident; between 15 December and 20 February.
WV--winter visitor; usually present for only a short period of the winter.
T--transient in spring and/or fall.
Abundance Status: The abundance status of each species is based on observation
in the appropriate habitat(s). Sporadic = numbers fluctuate significantly among
years. A species’ status as a transient is not indicated for summer, winter, or permanent residents unless it is different from the status as a resident.
||common or abundant; observed daily, usually in large numbers
||uncommon; frequently observed, usually in small numbers
||rare; more than 15 records; usually observed annually
||casual; 5-15 records; occasionally observed
||accidental; 1-4 records; a vagrant
||provisional; one or more records that meet acceptance criteria, but no definitive state record (i.e., either specimen, diagnostic photograph or audio, or multiple acceptable documentations)
||species formerly occurring in Missouri; now extirpated
||species formerly occurring in Missouri; now extinct
Distribution in Missouri: Letters in parentheses (n, sw, e, etc.) indicate general sections of Missouri without specific boundaries. No letters in parentheses
indicate that a species is widespread throughout the state. Miss. R. = Mississippi
River. Mo. R. = Missouri River.
Note: Taxonomy and nomenclature follow the American Ornithologists' Union Checklist
of North American Birds (1998) and subsequent supplements. The current AOU
Checklist is available at http://americanornithology.org/.