This is a list of all bird species ever seen in Missouri, as recorded by the Missouri Bird Records Committee of the Missouri Audubon Society.The following markings have been used:(C) = Casual: there have been between 5 and 15 sightings.(A) = Accidental: there have been between 1 and 4 sightings.(Ex) = Extirpated: The species, although not extinct, is no longer found in Missouri.(E) = Extinct: The species was once found in Missouri, but is now extinct.(I) = Introduced: The species was introduced, either directly or indirectly, to North America through the actions of humans.(H) = Hypothetical: Birds that have had a credible sighting reported, but have not been documented with a specimen or with a suitable photograph.Birds listed as either accidental, casual or hypothetical should not be expected to be found anywhere in Missouri with regularity. Except for the accidental, casual and hypothetical birds, only birds that are considered to have established, self-sustaining, wild populations in, or which migrate through Missouri, or, in the case extinct or extirpated species, have had such populations in Missouri in the past are included on this list. This means that birds that are considered probable escapees, although they may have been sighted flying free in Missouri, are not included on this list.This list is presented in taxonomic order and follows The Check-list of North American Birds (7th ed., 1998), published by the American Ornithologists' Union. The family accounts at the beginning of each heading reflect this taxonomy, as do the species counts found in each family accounts. Introduced, casual, accidental, hypothetical, extirpated and extinct species are included in the total species counts for North America and Missouri.