In the U.S. state of Colorado 519 species of birds have been documented as of September 2022 according to the Colorado Bird Records Committee (CBRC) of Colorado Field Ornithologists. This list is presented in the taxonomic sequence of the Check-list of North and Middle American Birds, 7th edition through the 63rd Supplement, published by the American Ornithological Society (AOS). Common and scientific names are also those of the Check-list, except that the common names of families are from the Clements taxonomy because the AOS list does not include them. Six of the documented birds are introduced species that are not native to North America, but were brought to this continent by humans. They are marked on this list as (I). Birds that are considered probable escapees, although they may have been sighted flying free in Colorado, are not included. Ducks, geese, and waterfowl Order: AnseriformesFamily: Anatidae The family Anatidae includes the ducks and most duck-like waterfowl, such as geese and swans. These birds are adapted to an aquatic existence with webbed feet, bills which are flattened to a greater or lesser extent, and feathers that are excellent at shedding water due to special oils. Black-bellied whistling-duck, Dendrocygna autumnalis Fulvous whistling-duck, Dendrocygna bicolor Snow goose, Anser caerulescens Ross's goose, Anser rossii Greater white-fronted goose, Anser albifrons Pink-footed goose, Anser brachyrhynchus Brant, Branta bernicla Barnacle goose, Branta leucopsis Cackling goose, Branta hutchinsonii Canada goose, Branta canadensis Trumpeter swan, Cygnus buccinator Tundra swan, Cygnus columbianus Wood duck, Aix sponsa Garganey, Spatula querquedula Blue-winged teal, Spatula discors Cinnamon teal, Spatula cyanoptera Northern shoveler, Spatula clypeata Gadwall, Mareca strepera Eurasian wigeon, Mareca penelope American wigeon, Mareca americana Mallard, Anas platyrhynchos Mexican duck, Anas diazi American black duck, Anas rubripes Mottled duck, Anas fulvigula Northern pintail, Anas acuta Green-winged teal, Anas crecca Canvasback, Aythya valisineria Redhead, Aythya americana Ring-necked duck, Aythya collaris Tufted duck, Aythya fuligula Greater scaup, Aythya marila Lesser scaup, Aythya affinis Harlequin duck, Histrionicus histrionicus Surf scoter, Melanitta perspicillata White-winged scoter, Melanitta deglandi Black scoter, Melanitta americana Long-tailed duck, Clangula hyemalis Bufflehead, Bucephala albeola Common goldeneye, Bucephala clangula Barrow's goldeneye, Bucephala islandica Hooded merganser, Lophodytes cucullatus Common merganser, Mergus merganser Red-breasted merganser, Mergus serrator Ruddy duck, Oxyura jamaicensis New World quail Order: GalliformesFamily: Odontophoridae The New World quails are small, plump terrestrial birds only distantly related to the quails of the Old World, but named for their similar appearance and habits. Northern bobwhite,