List of Anseriformes by population


This is a list of Anseriformes species by global population. Where possible, estimates are given for both the population of mature individuals, and the total global population. This list follows IUCN classifications for species names and taxonomy. Where IUCN classifications differ from other ornithological authorities, alternative names and species classifications are noted.
Anseriformes is the taxonomic order to which the ducks, geese, swans, and screamers belong. Version 15.1 of the IOC World Bird List describes 178 species belonging to Anseriformes, six of which are extinct. As of December 2025, BirdLife International has assessed 176 species ; 168 have had total or breeding population estimated. A variety of methods are used for counting waterfowl. For example, in North America, national and sub-national agencies use planes and helicopters to make aerial transects of breeding populations, and extrapolate these counts over the species' known ranges. Methodologies are continuously being refined; thus estimates can be expected to become more accurate over time. Forecasts can be made by studying habitat condition trends and by interviewing local experts. For more information on how these estimates were ascertained, see Wikipedia's articles on population biology and population ecology.
The first two birds in this list, the pink-headed duck and crested shelduck, retain a status of Critically Endangered on the IUCN Red List but may be extinct. The last sighting of the former occurred in 1948-1949, but some dispute this date and argue the species was last reliably documented in the 1930s, 1923, or 1910. The last pink-headed ducks in captivity died in the 1940s. Unconfirmed reports from Myanmar provide some hope this species is still extant.
The last confirmed reporting of the crested shelduck was in 1964 near Vladivostok. A disputed record from North Korea was claimed in March 1971. Unconfirmed reports from Northeast China are the best chance this species is still extant.
To be assessed as Critically Endangered, a species must have experienced a decline of at least 80% in the past ten years or three generations, or be projected to decline that much in the future ten years or three generations. Some species included in this list are rapidly approaching their minimum viable population, at which point the species would become functionally extinct.

Extinct species