This list of birds of Yukon includes species documented in the Canadian territory of Yukon. Unless otherwise noted, the list is that of the Yukon Bird Club (YBC). As of 2021, there were 348 species included in that list. Of them, 58 are casual and 60 are accidental; both terms are defined below. Four have been introduced to Yukon or elsewhere in North America. This list is presented in the taxonomic sequence of the Check-list of North and Middle American Birds, 7th edition through the 62nd Supplement, published by the American Ornithological Society (AOS). Common and scientific names are also those of the Check-list, except that Canadian English spellings are used and the common names of families are from the Clements taxonomy because the AOS list does not include them. The following tags are used to describe some categories of occurrence. (C) Casual - at least two records but not recorded every year per the YBC (A) Accidental - recorded only once per the YBC (I) Introduced - a species that has been introduced to Yukon by the actions of humans, either directly or indirectly Ducks, geese, and waterfowl Order: AnseriformesFamily: Anatidae 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. Snow goose, Anser caerulescens Ross's goose, Anser rossii (C) Greater white-fronted goose, Anser albifrons Taiga bean-goose, Anser fabalis (A) Tundra bean-goose, Anser serrirostris (A) Brant, Branta bernicla Cackling goose, Branta hutchinsii Canada goose, Branta canadensis Trumpeter swan, Cygnus buccinator Tundra swan, Cygnus columbianus Whooper swan, Cygnus cygnus (C) Wood duck, Aix sponsa (C) 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 American black duck, Anas rubripes (A) Northern pintail, Anas acuta Green-winged teal, Anas crecca Canvasback, Aythya valisineria Redhead, Aythya americana Ring-necked duck, Aythya collaris Tufted duck, Aythya fuligula (C) Greater scaup, Aythya marila Lesser scaup, Aythya affinis King eider, Somateria spectabilis Common eider, Somateria mollissima Harlequin duck, Histrionicus histrionicus Surf scoter, Melanitta perspicillata White-winged scoter, Melanitta deglandi Black scoter, Melanitta americana (C) Long-tailed duck, Clangula hyemalis Bufflehead, Bucephala albeola Common goldeneye, Bucephala clangula Barrow's goldeneye, Bucephala islandica Hooded merganser, Lophodytes cucullatus Common merganser,